You have to clean install 7; not upgrade
Follow these steps before you buy Windows 7:
Go to your Computer / Laptop Manufacturer’s website and see if Windows 7 Drivers are available for your Make and Model Computer / Laptop.
If not available, Windows 7 will not work correctly for you.
Run the “Windows 7 Upgrade Advisor”
Check to see if your System Specifications are compatible for Windows 7:
“Windows 7 system requirements”
Windows 7 Upgrade paths:
“Installing and reinstalling Windows 7”