Most beginners think…
…that a computer "remembers" everything inside its RAM, and that buying a bigger hard disk makes a slow PC fast.
Both are wrong — and the gap is exactly what separates someone who guesses from someone who fixes. RAM forgets everything the instant power is cut. And a 4 TB hard disk won't speed up a sluggish laptop one bit — an SSD plus enough RAM will. By the end of Path 1 you'll know which part does which job, and you'll never confuse the two again.
① Inside the Box — the six parts that matter
Open any desktop or laptop and the clutter shrinks to six jobs. Learn the job each part does and a "dead PC" stops being scary — it becomes a checklist. Here is the whole machine in one breath, using a kitchen as the analogy:
The six parts, one tap each
Flip each card — front is the part, back is what it actually does in plain words.
The cook. It reads instructions and does the actual work — Fetch, Decode, Execute, billions of times a second. Speed = brains of the PC.
The kitchen counter. Whatever the cook is working on right now sits here — fast to reach, but wiped clean the moment power is cut.
The cupboard (SSD/HDD). It keeps your files, apps and Windows even with the power off. Slower than RAM, but permanent and big.
The power + plumbing. The PSU feeds clean electricity; the motherboard connects every part so they can talk. No power, no plumbing — nothing else matters.
What actually happens when you press the power button?
Press Play to watch a healthy boot, then hit Break it to see the most common failure an IT desk meets on Monday morning.
▶ Power-on → desktop: the boot sequence
From a cold press of the button to a working Windows screen. Press Play for the healthy path, then Break it to see the failure.
The CPU — the cook
The CPU is the brain. It does three things in a tight loop, called the instruction cycle: Fetch the next instruction from RAM, Decode what it means, then Execute it (do the maths, or move some data). It repeats this billions of times a second. Watch one trip around the loop:
▶ How the CPU runs one instruction
The fetch-decode-execute cycle. Press Play for the healthy path, then Break it to see what bad RAM does to it.
The power supply (SMPS / PSU) — the feeder
Your wall socket gives AC (alternating current). Every part inside a PC needs steady DC (direct current). The PSU (also called an SMPS) bridges that gap and splits it into three rails: +12V (CPU, GPU, fans), +5V and +3.3V (board logic, drives). It also has a fan to keep itself cool.
Unplug the PSU from every component. Bend a paperclip into a U and bridge the green wire (PS_ON#, pin 16) to any black wire (ground) on the 24-pin connector. Plug in and switch on: if the PSU fan spins, the unit is broadly alive. No spin = dead PSU.
Pause & Predict
A PC is completely dead — no fans, no lights, nothing. Before you touch the CPU or RAM, which one part should you suspect first, and why? Type your guess.
The CMOS battery — the tiny clock-keeper
That coin-shaped battery on the board is the CMOS battery — a CR2032, about 3 volts (a single coin cell is 3V — if anyone tells you "6V", that's two cells in series, which motherboards do not use). It keeps two things alive while the PC is unplugged: your BIOS/UEFI settings and the real-time clock (date and time).
Signs it's dying: the clock keeps resetting; you see "CMOS Checksum Error" or "Time of day not set" on boot; BIOS settings reset to default every time you fully power off. Fix: pop in a fresh CR2032.
BIOS / UEFI — the starter
BIOS (and its modern replacement, UEFI) is firmware baked onto the motherboard. At power-on it runs POST (the hardware check), then follows the boot order to find an operating system and hand over control. You enter the setup screen by tapping a key right after power-on — usually F2, F10, F12, or Delete depending on the maker.
UEFI vs old BIOS: UEFI adds a graphical, mouse-driven interface, supports drives bigger than 2 TB, boots faster, and enables Secure Boot (which Windows 11 needs). Most machines today are UEFI even though people still say "BIOS".
🖥️ This is the screen you'll use to boot from a USB — UEFI Setup → Boot → Boot Option Priorities. (Recreated for clarity — your firmware will look close to this.)
RAM — the counter (and its types)
RAM is the fast, temporary workspace the CPU uses for whatever is open right now. It is volatile — switch off, and it's blank. That's why unsaved work is lost in a power cut. Two big families:
- SRAM — extremely fast, expensive, tiny. Used inside the CPU as cache.
- DRAM — slower but cheap and large. This is your main system memory (the sticks you can see).
The DRAM you buy today is DDR (Double Data Rate). Quick map of what's current in 2026:
| Type | Where you'll see it | Status in 2026 |
|---|---|---|
| DDR4 | Older / budget desktops & laptops | Legacy, still everywhere |
| DDR5 | New desktops & laptops | The mainstream standard |
| LPDDR5 / LPDDR5X | Phones, tablets, thin laptops | Low-power mobile standard |
| GDDR6 / GDDR7 | On graphics cards (VRAM) | GDDR7 leads on new GPUs |
Which type of memory loses everything it holds the moment the computer is switched off?
Storage — the cupboard (HDD, SSD, NVMe)
Storage is where everything lives when the power is off — Windows, your apps, your files. Unlike RAM, it's non-volatile. Three things to know:
| Drive | How it works | Speed & use |
|---|---|---|
| HDD (Hard Disk Drive) | Spinning magnetic platters + a moving head | Slow, cheap, huge — great for backups & bulk storage |
| SSD (Solid State Drive) | Flash memory, no moving parts | Fast, quiet, durable — the right home for Windows |
| SSHD (Hybrid) | HDD + a small SSD cache | A middle ground; rare today |
How they plug in (interfaces): SATA is the older, slower connection (~550 MB/s, fine for everyday use). NVMe SSDs ride the very fast PCIe bus (several thousand MB/s) — roughly 7,000 MB/s on PCIe 4.0 and ~14,000 MB/s on PCIe 5.0 and are the modern standard for the Windows drive. SAS is an enterprise interface built for 24/7 servers.
Input / Output devices
Finally, the parts you actually touch. Input devices send data in (keyboard, mouse/touchpad, microphone, scanner, webcam). Output devices show results out (monitor, printer, speakers, projector). And some do both — a touchscreen shows the picture and takes your taps; a headset plays sound and has a mic; a USB drive both reads from and writes to the PC.
② Set Up Windows — from bare machine to working desk
Hardware is useless without an operating system. On most office and college machines that means Windows. Here's how to install it, get every part working with drivers, add the everyday software, and set up email — the exact jobs you'll do in your first weeks.
Which Windows?
Windows 11 is the current flagship (centered Start menu, modern look). Windows 10 is the previous standard, still widely used. Older 7/8 are retired. Within each, Home is for personal use; Pro / Enterprise add business features like BitLocker drive encryption and the ability to join a company domain.
Installing Windows 11 — the two ways
First, the machine must meet the minimum requirements: a supported 64-bit CPU (1 GHz, 2+ cores), 4 GB RAM, 64 GB storage, UEFI + Secure Boot, and TPM 2.0 — and the CPU must be on Microsoft's supported-processor list, which is what blocks many older-but-fast chips even when the speed looks fine. The TPM/Secure Boot checks are the usual reason a perfectly good PC is "blocked" — they're often just switched off in BIOS.
- Upgrade (keep your files): already on Windows 10? Download the Installation Assistant from Microsoft's site → Accept & Install → restart. Your apps and files carry over.
- Clean install (fresh start / new PC): use the Media Creation Tool to make a bootable USB stick (8 GB+, everything on it is erased) → boot from the USB → Install now → pick the drive → follow the prompts.
Rahul at TCS faces this
A brand-new ThinkPad runs the PC Health Check and gets a red "This PC can't run Windows 11" — but the spec sheet says it's a current Core Ultra 7 with 16 GB RAM. Everyone assumes the laptop is faulty.
The CPU is fine. TPM (often called PTT/fTPM) or Secure Boot is disabled in firmware — common on machines shipped with a custom or older image.
Run tpm.msc in Windows; if it says "Compatible TPM cannot be found", reboot into BIOS and look under Security/Advanced.
Enable PTT/fTPM and Secure Boot, save and exit. Re-run the PC Health Check — it now passes.
Back in Windows, tpm.msc shows "The TPM is ready for use" and the upgrade button is no longer blocked.
A capable, modern laptop fails the Windows 11 check. The CPU, RAM and storage are all well above the minimums. What is the most likely thing you need to switch on?
Drivers — the translators
A driver is the small piece of software that lets Windows talk to a piece of hardware. No driver, no working device. After a clean install you'll often install chipset, graphics, network and audio drivers. The place to check them is Device Manager — a yellow ⚠ means a device has no working driver.
🖥️ The screen for checking drivers — right-click Start → Device Manager. A yellow ⚠ is the tell-tale of a missing/broken driver. (Recreated for clarity.)
You can also list every installed driver from the command line:
driverquery
Module Name Display Name Driver Type Link Date =========== ====================== ============ ================== 1394ohci 1394 OHCI Compliant... Kernel 12-05-2025 10:14 ACPI Microsoft ACPI Driver Kernel 12-05-2025 10:14 ... (one row per installed driver) ...
Choosing a laptop processor (2026)
You'll be asked "which laptop should we buy?" Learn the tiers, not the code-names (those change yearly). Intel rebranded its premium line to Core Ultra (with a Series number, e.g. Series 1/2/3) and keeps a value Core 3/5/7 line; AMD ships Ryzen 3/5/7/9 (and the AI-focused Ryzen AI 300); Apple is on M-series (M5); Qualcomm's Snapdragon X / X2 Elite powers Windows-on-ARM.
| Tier | Intel | AMD | Good for |
|---|---|---|---|
| Entry | Core 3 / Ultra 3 | Ryzen 3 | Browsing, MS Office, email |
| Mid (most popular) | Core 5 / Ultra 5 | Ryzen 5 | Multitasking, light creative, study |
| High | Core 7 / Ultra 7 | Ryzen 7 | Video editing, dev work, gaming |
| Top | Ultra 9 | Ryzen 9 | Heavy professional workloads |
Apple Silicon (M5 / M5 Pro / M5 Max) leads on battery + performance-per-watt for macOS; Snapdragon X/X2 brings all-day battery to thin Windows "Copilot+" laptops.
Day-one free software
After install, these free, trusted apps cover most needs: Chrome / Firefox (browser), 7-Zip (open ZIP/RAR/7z), VLC (plays any video), LibreOffice or Microsoft 365 (documents), Adobe Acrobat Reader (PDFs), Bitwarden (password manager), and Microsoft PC Manager (cleanup + startup control).
Microsoft Office & Outlook
Microsoft Office / 365 is the productivity suite — Word (documents), Excel (spreadsheets), PowerPoint (slides), Outlook (email + calendar), plus OneNote/Access. You can get it as a 365 subscription (always updated, cloud storage), a one-time Office 2024 purchase, or free Office on the web.
Setting up Outlook: open Outlook → type your email → Connect → enter password → it syncs mail, calendar and contacts. If auto-setup fails for a custom domain, use File → Account Settings → New, tick "set up manually", choose IMAP or POP, and enter the server settings from your provider.
PST vs OST — the two Outlook data files interns confuse most:
| OST (Offline Storage Table) | PST (Personal Storage Table) | |
|---|---|---|
| What it is | A synced cache of a server mailbox | A portable local archive / export |
| Syncs with server? | Yes — auto, when online | No — independent of the server |
| Used with | Exchange, Microsoft 365, IMAP | POP3, archiving, moving mail |
| Safe to delete? | Yes — rebuilds from the server | No — it's the only copy |
An archive file is a .pst that moves old mail off the server to free space — it lives on your hard drive, so it must be included in your backups (don't keep it in a cloud-synced folder, that corrupts it).
Control Panel & Windows 11 Settings
Two places to configure Windows. Control Panel (search "Control Panel") is the classic dashboard — System & Security, Network, Hardware & Sound, Programs, User Accounts, etc. Settings (press Windows + I) is the modern app — Display & scale, Dark mode, Windows Update, App permissions (camera/mic/location), and Startup apps (turn off heavy ones to boot faster). Tip: the modern End task right-click on a taskbar app (enable it under System → For developers) force-closes a frozen app.
🤖 Ask the AI Tutor
Tap any question — instant, scoped to this lesson. No login, no waiting.
Pre-curated from Microsoft Learn + hardware-vendor docs + community Q&A, scoped to this lesson. For a live problem on a real machine, paste your details into chat.techclick.in.
📝 Wrap-up assessment — six more
You've answered 4 inline. Six left. 70% (7 of 10) marks the lesson complete on your profile. Tap Submit all answers at the end.
🧠 In your own words
Type one line: Explain the difference between RAM and storage to someone who has never used a computer. Then compare to the expert version.
🗣 Teach a friend
Best way to lock it in — explain it in one line to a teammate. Tap to generate a paste-ready summary.
📖 Glossary
- CPU (Central Processing Unit)
- The "brain" of the PC — it fetches, decodes and executes instructions billions of times a second.
- RAM (Random Access Memory)
- Fast, temporary "desk space" the CPU works on. It is volatile — emptied at power-off.
- Volatile / Non-volatile
- Volatile memory (RAM) loses its contents without power; non-volatile storage (SSD/HDD) keeps them.
- SSD / NVMe / HDD
- SSD = flash storage, no moving parts, fast. NVMe = an SSD on the very fast PCIe bus. HDD = spinning magnetic disk, slow but cheap and big.
- PSU / SMPS
- Power Supply Unit (a Switched-Mode Power Supply) — converts wall AC into the clean +12V/+5V/+3.3V DC the PC needs.
- CMOS battery
- A coin cell (CR2032, ~3 V) that keeps the clock and BIOS settings alive while the PC is off.
- BIOS / UEFI
- The motherboard's firmware that runs at power-on, checks the hardware (POST) and starts the operating system. UEFI is the modern version.
- POST (Power-On Self-Test)
- The quick hardware check the BIOS/UEFI runs at startup; failures show as beep codes or board LEDs.
- Driver
- Small software that lets Windows talk to a piece of hardware (GPU, Wi-Fi, printer).
- TPM 2.0 / Secure Boot
- A security chip and a boot check that Windows 11 requires; often just need switching on in BIOS.
- Partition (GPT / MBR)
- A logical division of a drive. GPT is the modern style (huge drives, 128 partitions); MBR is legacy (2 TB, 4 partitions).
- File system (NTFS / exFAT / FAT32)
- How a drive organises files. NTFS for Windows drives, exFAT for cross-device USBs, FAT32 only for old/small media.
- PST / OST
- Outlook data files. OST = a synced cache of a server mailbox; PST = a portable local archive/export.
📚 Sources
- Microsoft Support — Windows 11 system requirements (TPM 2.0, Secure Boot, supported-CPU rule). support.microsoft.com
- Microsoft Learn — Windows support for hard disks exceeding 2 TB (MBR 2 TB vs GPT). learn.microsoft.com
- Microsoft Support — WMIC removal from Windows + System File Checker (SFC) and Startup Settings / Safe Mode. support.microsoft.com
- Intel — Intel Core Ultra processor names and numbers (Core Ultra Series 1/2/3). intel.com
- AMD — Ryzen AI 300 Series processors; Apple Newsroom — MacBook Pro with M5 Pro / M5 Max. amd.com · apple.com
- Kingston / Crucial — DDR5 vs DDR4 and PCIe Gen 4/5 NVMe SSD speeds. kingston.com · crucial.com
- NTFS.com / Corsair — NTFS vs exFAT vs FAT32 limits and how to test a PSU (paperclip test). ntfs.com · corsair.com
What's next?
You now know what's inside the box and how to set it up and fix it. The natural next step in your internship track is how those boxes talk to each other — IP addresses, DNS, switches and routers — and then your first hands-on lab.