If you really have IE5 then obviously that needs to be upgraded to IE9. Run your Windows Updates in Vista to make sure everything is fully up to date including SP's.
If there are issues flagged during the Upgrade Advisor phase before install begins, be sure to resolve all of them. If in doubt uninstall the program or device in Control Panel or Device Manager.
Type msconfig in Start Search box, rightclick result to Run as Admin, uncheck everything in msconfig>Startup and >Services tabs (after Hiding All MS Services), reboot then try Upgrade again.
Remember that you are struggling here to get an inferior in-place Upgrade. Nothing compares to a fresh
Clean Install which will teach you a lot about your computer. With Windows 7 backup imaging you can save a backup image once set up so you never have to reinstall again - just reimage the HD or replacement in 20 minutes.