I tried upgrading from Windows ME to XP once upon a time. A disaster. My brother is an IT consultant and believes upgrading, as opposed to a clean install, is to be used only as a last resort.
A clean install is always preferable to an upgrade. Especially in a multiple-computer environment. OTOH. Going from ME to XP may have had some difficulties associated with the stability factor. Things have changed in the last 10 years. Going from XP to Win7 will be a breeze. As I mentioned, today we have USB flash memory sticks and external hard drives that work great, or you can reply on DVD’s and CD’s to transfer your personal info and system data. There are high speed cable transfer setups that work great too. Also, Windows Easy Transfer looks pretty reliable.
My point. There are many viable options available to get you from XP to Win7 safely.