I agree with the suggestion for a clean install. The thing most people don’t realize is that hard disks have errors, and when they get old enough, the data on them gets corrupted. Eventually some operating system file gets corrupted, and things stop working. In later versions of Windows, Microsoft introduced a feature that keeps a backup copy of operating system files, and a utility, System File Checker (sfc.exe), that can detect and correct corrupted OS files. But because you are on XP, that isn’t an option.
So back up everything important and do the clean install.
Side question on that subject;
Is it possible to do a 'repair' install of XP so that it simply updates OS files, etc. and does not wipe the drive so that all personal data and installed programs are gone?
I've done it once before and it got rid of all non-Windows data.
I have searched and seen about a 50-50 mix of those who say it is non-invasive versus those who say otherwise.
I have a PC that says "WinXP can't start because of corrupted or missing C:\windows\system32\config".
I've tried running the Recovery Console from XP disk and chkdsk and Windows does start but after shutdown, the next boot does not run Windows. Only the same error message. I'm thinking a re-install of WinXP would fix it...but not at the expense of all my installed programs.