Could you give a little more information as to the process and how far along the upgrade process it was before you got stuck on the Blue colored screen?
I have not upgraded one of my Windows 7 installs and don't intend to but it does seem certain problems are related to that process. But it may take some time for an upgrade to complete. If you have certain types of devices, maybe even USB devices, it may cause problems. Older software may be involved but really hard to tell.