I feel your pain and frustration in relation to re-installing Windows.
However, it is likely the "best" option to improve performance.
I am trying to avoid this on my W98 machine, but have concluded that I have no other "realistic" choice.
There are a couple of things that happen over time that slow things down.
1. Extra fonts: Each installed font uses some system resources. If you can identify un-need fonts, and uninstall them, this will help.
2. System files: Over time, youbuild up extra, un-needed, and obsolete system files (DLLs). Some of these also use up system resources.
3. (The "BIG" Problem) The Registry grows every time you install, update or access software.
The registry tools in Fix-It (I use it myself)do a decent job of identifying and correcting "errors" in the registry.
However, none of the tools that I have tried clean out the "bloat" that builds up over time.
Change hardware, there will be leftover keys in the registry from the old hardware. Since the files the keys are linked to were not deleted, Fix-It won't identify that there is an error.
Un-install, or upgrade software, the same thing happens.
Microsoft itself, creates updated keys for security fixes without deleteing theold keys.
Some updates add a new subkey to the old key that points to the new key.
So, blame Microsoft, blame bad software, blame poor un-install programs, the fact is Windows needs to be purged every so often in order to keep performance at an aceptable level.
Some peers have posted that they re-install Windows every 6 months!!!
Realistically, Windows 9X has about a 2 year run life for the "average" user.
The more you swap hardware and software, the more often you need to wipe the drive, and re-install Windows.
Chas