System reserved parition blocking Windows 7 Reinstall

1) Disable UAC.

Disable User Account Control (UAC) the Easy Way on Win 7 or Vista - How-To Geek

2) Disable Hibernation. This will also delete the hibernation file.

Hibernate - Enable or Disable

If you right click the drive icon and go to properties you should see a "Disk Cleanup" option that can free up a lot of space. Under the "More Options" tab you can free up even more space used by system restore.

I am not sure why you would need to free up a lot of HD space to run a Repair install. Are you running the Win7 installer from the desktop to do the upgrade install, or booting the installer?

I am running the Windows 7 installer from the desktop to do the upgrade install... should I rather boot directly to the CD ?

"Boot the installer to do a Clean Install"

==> what do you mean ? I currently double-click on the Setup.exe file on the disk from Seven Desktop.

Right. Have you tried the Clean Boot procedure to see if iRepair Install will run?

Keep in mind you have the other option to Clean Reinstall.

I will try today, keep you posted... I guess it's my last chance......

The problem of a potential clean reinstall is that I do not want to loose my iTunes 70Gb Music library !

Back up your Itunes music and when you reinstall ITunes it will find and reconstruct your Music Library including album art if u want.

I don't use Itunes myself, but have done enough clean reinstalls for those who do that I know it is a surprising piece of cake, as long as you are sure you back up the relevant data files which are normally in Music folder.

Others may have additional advice.