up to 32%
I wasn’t able to figure out what was happening from your post
When you try to boot Windows XP, exactly what do you see? It sounded like you were booting Safe Mode.
Any time (these days) your computer acts in a manner that is unfamiliar, or not "normal" you must consider nefarious forces at work. This at least is my security conscious mind set.
It could very well be hardware issues at play, but until other possibilities are ruled out; the Devils Advocate should be in the back, if not the forefront, of your mind.
Now these are predicated on certain assumptions based upon the limited information provided. Some of those assumptions are (and forgive me if they are incorrect): You're running Windows; you're running IE; you're system account has Admin privledges; You have Java, and Java Script turned on; you have little or no firewall protections; multiple people in your household use the same account...