I just had a virus removed by a technician which required him to wipe the drive. Then he advised me to scan my backup with Norton Security.
After the scan, no virus was found. So I went ahead and installed the backup. But then I learned all my files on the backup were corrupted and useless to me and the virus is now back on the desktop. So I am wondering, if I remove and replace the hard drive, would it be safe to use the desktop as a second computer in case my new laptop computer needs repair?
Get the free trial version of Malwarebytes install, boot to safe mode and let it do a scan and remove whatever nasties it finds. After that and if the system is happy. Delete that backup and redo it with you now clean system clean system. I'd not recommend norton as I've found it mostly useless at detecting or protecting anything.
Ok, will do. But what about my question? Can a virus affect other components of a computer? I want replace the hard drive and keep the desktop computer available in case my new laptop needs repair. I am concerned about the memory and any other components that a virus will attack.
Technically it's possible other components could be affected, but it's doubtful. Memory can't be as it's non volatile. The board could be but it'd be way too much trouble to pull off and would need access to the machine. I'd personally just wipe the drive and reinstall
Hard drive controllers have also been infected, but we're talking nation-state sponsored malware campaigns and BIOS but same thing. What's much more likely is there is either malware in the data backup or the user is getting hit by a drive-by exploit on a website.
I'm guessing in the backup, so I'd be deleting that and start fresh. Only download drivers from intel, amd etc and once completed a backup kept but off the machine. When creating the install media I'd do that on a known clean machine.