Ten Lab PCs and Three Failures
The school computer lab has ten PCs, each with 4 GB RAM, a 500 GB hard disk and Windows 10. Three PCs fail on the same morning. PC-3 gives repeated beeps and no display. PC-7 shows “No bootable device” after the school electrician replaced a power cable. PC-9 is extremely slow, with disk usage at 100%, and shows “Windows Update pending restart”. The lab assistant wants to reinstall Windows on all three and buy three new hard disks. The available budget is ₹8,000, and the store has one spare 4 GB RAM stick and one SATA cable. The lab assistant asks you to decide what to do first, what to spend on, and what to avoid.
1. For each PC, state the most likely cause and the first three checks you would perform, in order. Explain why reinstalling Windows first is a poor decision for at least two of them.
Read the worked answer
PC-3, repeated beeps and no display: likely a POST hardware fault, commonly RAM not seated, a failed RAM stick, or a display connection. Checks: (1) reseat the RAM and try one stick at a time; (2) check the monitor cable and monitor power; (3) if the board has onboard video, remove any add-on card and retest. Reinstalling Windows cannot fix a machine that does not reach POST, so it is wasted time.
PC-7, “No bootable device” after a power-cable replacement: likely the SATA data cable or power cable was disturbed, or the boot order changed. Checks: (1) enter BIOS/UEFI and confirm the disk is detected; (2) reseat the SATA data and power cables, trying the spare SATA cable; (3) check boot order and, only then, the disk's partition/boot record. Reinstalling Windows before checking cable and detection risks destroying data for a simple loose-cable fault.
PC-9, 100% disk and pending update: likely a Windows Update or background service still running, a nearly full disk, or a failing disk. Checks: (1) allow the pending restart/update to finish and observe; (2) check free space and disk health (SMART); (3) scan for malware and check startup programs.
2. Using the ₹8,000 budget, decide what to buy and what to do with the spare RAM stick and SATA cable. Justify each choice.
Read the worked answer
Do not buy three hard disks or reinstall three operating systems on the first morning. Use the free diagnostics first.
- Spare 4 GB RAM stick: use it to test PC-3. If PC-3 boots with the spare stick, the original RAM is faulty; if it still beeps, the fault is elsewhere. This costs nothing and avoids an unnecessary purchase.
- Spare SATA cable: use it on PC-7 after checking BIOS detection. If the disk appears with the new cable, the repair is essentially free.
- PC-9: no purchase yet. A restart and update may clear the 100% disk usage. If SMART shows reallocated sectors, then a replacement disk is justified.
A sensible budget keeps most of the ₹8,000 unspent until diagnostics identify a real failed part. Buying three disks in advance may waste money and does not address PC-3's POST beeps or PC-7's loose cable.
3. Suppose PC-9's SMART report shows a rising reallocated-sector count. What is the correct next step, and how does it change your plan for the other two PCs?
Read the worked answer
A rising reallocated-sector count is evidence of a failing disk, not merely a slow Windows installation. The correct next step is to back up the user data immediately, replace that disk, reinstall Windows or restore an image, and then verify the update and disk health. The replacement should come from the budget, but only for PC-9.
It does not change the plan for PC-3 and PC-7. PC-3 still needs POST-level diagnosis, and PC-7 still needs cable and BIOS detection checks. A single failing disk is not evidence that all ten PCs need new disks. The lab assistant's original plan overgeneralises one fault into three and spends the budget before diagnosis; the correct approach is evidence-led repair, with replacement limited to the machine whose SMART data supports it.