You could use Upgrade version to clean install as long as you have qualifying Vista - installed or not.
Back up your files externally, make your Recovery DIsks or save a backup image of the entire HD first so you have a path back to factory condition. Then wipe the HD of all code to get cleanest install: SSD / HDD : Optimize for Windows Reinstallation
If you install to wiped HD, the installer will issue a 100mb System Reserved boot partition which conveniently places the Repair Console (normally only on the DVD or Repair CD) on the F8 Advanced Boot Tools menu. So boot the installer, choose Custom Install and then Drive Options to partition as you wish and format: Clean Install Windows 7
The installer is mostly driver
-complete, with newer arriving quickly via optional Windows Updates. Just in case, have your Wireless driver on flash stick or CD so you can get online quickly. Then enable hardware driver auto-updating
and check for optional Updates.
still missing in Device Manager can be found on the Support Downloads webpage for your model computer or device. Driver Install - Device Manager
Install updates and then programs slowly over time to gauge performance after each. Don't let any programs write themselves into msconfig>Startup as they slow startup, become freeloaders on your RAM/CPU and can spy on you. I only allow AV and gadgets. Startup Programs - Change
Use a lightweight free AV like MS Security Essentials which works perfectly with Windows 7 Firewall. http://www.microsoft.com/security_essentials/
When it is finished, clean and order the HD perfectly using state-of-the-art free CCleaner then Auslogics Disk Defragger monthly. CCleaner - Free software downloads and software reviews - CNET Download.com http://download.cnet.com/Auslogics-D...-10567503.html
Then save a Windows 7 Backup image externally so you never have to reinstall again, just reimage the HD (or replacement) using DVD/Repair CD with the stored image. Backup Complete Computer - Create an Image Backup