Prof Drapes,
In addition to the wise advice above, (or is it below?), my XP SP3 will only allow me to access MS sites via IE. As it is XP, it is not the latest IE that works, but an earlier one. I keep forgetting that. It won't allow me to use either Firefox, which is my normal browser, nor Chrome.
As I do a daily CCleaner, I have not had the issues that Sprogs says might be there.
I dunno what bits of software MS download to "verify" my system, but maybe in your re-build you've lost that bit of MS software?