I started out building my current computer with pretty up-to- date hardware, and originally ran Vista Business SP1 on it. By the time Windows 7 RC1 came out, I had upgraded to Vista SP2 and was still sick of Vista’s aggravating … That’s right – I could not upgrade the RELEASE CANDIDATE of their operating system to the official release version.

See more here:
Windows 7 upgrade rant. « Fireball Spam