I 'upgraded' from Vista Business to Windows 7 Home Premium on a Lenovo Laptop. Since it was not a straight upgrade, ie Business to Business or Home to Home, I needed to do a complete reinstall, as against an upgrade. Prior to this I checked the Lenovo sight and they recommended programmes that needed to be deleted prior to changing to Win 7. Programmes such as Password Manager and the Thinkpad system come to mind. It would be worth you checking the computer manufacturers site for info, plus windows have a piece of downloaded software that can check your system for you and determine whichj will or won't work.
It took me pretty much most of a full day to remove, install and reload. A few problems but managed to solve them and I am not patrticularly computer literate.
Good luck.