Desktop PC

Step-by-step desktop PC check when buying or for yourself. Works for new and used PCs.

1

Quick check

5–10 minutes, no software to install

  1. Visual inspection

    Inspect the case and dust inside (if there is a glass panel). Make sure all fans spin: CPU, case and GPU fans.

  2. Power on

    Power it on: no speaker beeps, grinding or loud fan noise at startup.

  3. Specs

    Match the CPU, RAM and GPU in Device Manager. Make sure no device shows a yellow triangle.

  4. Monitor

    Check the panel for dead pixels and backlight bleed.

    Open online test →

  5. Keyboard

    Test every key.

    Open online test →

  6. Mouse

    Check clicks, the wheel and smooth cursor movement.

    Open online test →

  7. Ports and connectors

    Plug a flash drive or cable into every USB (especially the rear ones on the motherboard), check audio jacks, HDMI and DisplayPort.

  8. Sound

    Play a video: check speakers or headphones and the microphone.

  9. Network

    Test Wi-Fi (if there is an adapter) and the Ethernet (LAN) cable.

  10. CPU test

    Run the online CPU test — check compute speed and stability under load.

    Open online test →

  11. GPU test

    Run the online GPU test — check FPS and stability under graphics load.

    Open online test →
2

Medium check

15–20 minutes, built-in Windows tools

  1. Disk

    Check the SSD/HDD with chkdsk or CrystalDiskInfo.

  2. Load test

    Run a heavy 4K video or a simple game: the PC must not shut down or show a blue screen.

  3. Temperatures

    Install a light tool like HWMonitor and check CPU and GPU temperatures at idle and under load.

3

Full check

30–60 minutes, special utilities required

  1. CPU and system

    Run an AIDA64 or OCCT stress test (10–15 min): watch temperatures and throttling.

  2. Graphics card

    Run FurMark or Superposition: check for artifacts (stripes, flickering) and overheating.

  3. RAM

    Test memory with the Windows tool (mdsched.exe) or TestMem5.

  4. Storage

    CrystalDiskInfo (health, power-on hours) plus Victoria to scan for bad sectors.

  5. Power supply

    Check voltage stability with OCCT (Power section) or a multimeter if you have the skills.

Related checklists

LaptopGraphics cardPower supply

How to test a PC before buying — full guide

Testing a desktop PC before buying requires a systematic approach: unlike a laptop, a PC has many separate components, and each one can have hidden issues. This checklist will help you test the entire computer step by step: from a visual inspection to a full stress test of all components. Works for new and used PCs of any configuration.

The quick check takes 5–10 minutes with no software. Inspect the case inside and out (if it has a glass side panel): evaluate the dust level, cable management and fan condition. Make sure all fans spin: the CPU cooler, case fans and GPU fans. Power on the PC and listen: there should be no speaker beeps, grinding, loud noise or clicks. Open Device Manager and match the CPU, RAM size and GPU model to what is claimed. Make sure there are no devices with yellow triangles — this means missing or failed drivers. Test every USB port (especially the rear ones on the motherboard), HDMI, DisplayPort and audio jacks. Run the online CPU and GPU tests on FullTestPC — they will show performance and stability under load.

The medium check takes 15–20 minutes using built-in Windows tools. Test the storage with the chkdsk command in the command prompt (as admin): chkdsk C: /f /r — this checks the file system and finds bad sectors. Alternatively use CrystalDiskInfo — a free tool that shows SSD/HDD health (SMART), power-on hours and boot count. Health should be «Good» or 95–100%, power-on hours should not exceed 30,000 for HDD and 5 years of writes for SSD. Install HWMonitor and check CPU and GPU temperatures at idle and under load. Run a heavy 4K video or a simple game for 10 minutes: the PC must not shut down, reboot or show a blue screen (BSOD).

The full check takes 30–60 minutes and requires specialised tools. Run AIDA64 System Stability Test or OCCT — they load the CPU, GPU, memory and storage at the same time. Run the test for 15–20 minutes and watch the temperatures: the CPU should not exceed 85°C, the GPU — 85°C. If errors appear or the PC reboots — it is a power supply or overheating issue. Test RAM with the built-in Windows tool (Win + R → mdsched.exe) or TestMem5 — the test takes 20–30 minutes and finds bad memory cells. Test the storage with Victoria — the program scans every sector and shows a health map. Test the power supply with OCCT (Power section) or a multimeter: voltages on the +3.3V, +5V and +12V rails should be within ±5% of nominal.

Common PC issues to watch for. A worn power supply shows up as random reboots under load, fixed only by replacement. Bulging capacitors on the motherboard are visible on inspection and require board replacement. A dust-clogged cooling system causes overheating, cleaned with compressed air. Dead RAM cells show up as blue screens, fixed by replacing the stick. Worn storage shows up as slow boot times and read errors, fixed by replacement. Broken USB ports on the motherboard cannot be fixed, only bypassed with a PCI-E card. When buying a used PC, check the BIOS for no passwords and make sure Windows activation is tied to the hardware (UEFI key), not the seller's account.