Help
Something not working? Find the problem below. Most have a quick fix.
Windows says "Windows protected your PC"
- Click More info, check the app name is KnowYourBuy.exe, then click Run anyway.
- This appears for apps Windows hasn't seen often. It isn't a virus warning.
Antivirus blocks or deletes Know Your Buy
- Hardware-reading tools are sometimes flagged because they read sensors at a low level.
- Check your copy is genuine using the fingerprint on the download page. If it matches, restore it from the antivirus quarantine or allow it.
- If it doesn't match, delete it and download it again from this site.
No one can approve the administrator prompt
- Know Your Buy needs administrator access to read temperatures and drive health, so it can't run without it.
- Ask the seller to sign in with the laptop's administrator account. A laptop where no one knows the admin password is worth asking about before you buy.
Know Your Buy doesn't open
- Check the laptop runs 64-bit Windows 10 (version 1809 or newer) or Windows 11.
- Copy KnowYourBuy.exe from the USB stick to the desktop and run it from there. Some sticks are slow or read-only.
- Make sure the stick has some free space for reports and logs.
Processor temperatures are missing or look identical on every laptop
- Exact core temperatures need the optional PawnIO driver. Accept the offer when Know Your Buy starts, then run the test again.
- Without it, many laptops report a fixed dummy value. Know Your Buy spots readings that never move under load, ignores them, and judges slowdown from measured work speed instead, with lower confidence.
There's no Fan test
- This laptop hides its fan speed from Windows, so Know Your Buy hides the Fan test. That's normal on many laptops.
- The processor test and stress test still catch overheating caused by a weak fan.
The battery test says to restart Know Your Buy
- The charger was plugged in or unplugged during the test, so Windows' battery reading may be out of date.
- Close Know Your Buy and open it again to get a fresh reading.
The storage test is slow or writes less than 1 GB
- Know Your Buy scales the write test down when the drive is nearly full, to stay gentle on the seller's laptop.
- Hard drives are much slower than SSDs, so their test takes longer. That's expected.
- If drive health counters aren't readable, Know Your Buy judges the drive from its speed and shows a lower confidence.
The PDF report didn't save
- Reports are saved to the KnowYourBuy-Reports folder next to KnowYourBuy.exe, on the USB stick.
- If the PDF can't be created on that laptop, Know Your Buy saves an HTML report instead. Open it in any browser.
Where are the logs?
- In the KnowYourBuy-logs folder next to KnowYourBuy.exe. If the stick can't be written to, they go to the laptop's temporary folder under KnowYourBuy\logs.
- Exporting a report also saves a .json file with all the raw numbers.
Still stuck?
Check the FAQ. A support email is coming soon. When you write, attach the log file from the KnowYourBuy-logs folder.