Just wondering. Doesn't the error say which Microsoft application has encountered an error and needs to close? For example, Internet Explorer or Word.

If it's one the Office applications, you might be able to solve the problem by re-installing Office (if you have the CDs). If it's Internet Explorer v6, you could download and install Internet Explorer v7.

Like Wagner, I have multiple PCs running XP and Vista. My main PC is running XP (because the hardware is not great) and I have dozens of applications and many devices installed. It's as stable as rock.