Should you do an upgrade or a
clean install of a new operating system? You may want to review the
following:
Upgrading
vs. Clean Installation
Vista
Performance Shootout: Upgrade vs. Clean Installation
Generally, you will reduce the risk of problems by doing a clean install
(you cannot use an upgrade version for a clean install), but it requires
additional work. You will have to make sure to save all of your data,
software keys, email files, and so forth on backup media (external hard
drive, thumb drives, CD/DVDs, etc.) to assure that you can load them on the
new OS. (You should also do this for an upgrade in case it goes bad).
If you upgrade a computer with problems, those problems may persist in the
upgraded OS or render it difficult to use. Frequently, a clean install
will avoid driver problems, software compatibility problems, etc.