If all else fails and you have a retail Windows 7 installation disc, then you could do a custom install
of Windows 7 and still save everything you have in your current installation.
A custom install is like a clean install except that it will also add a C:\Windows.old
folder during installation that contains a complete copy of your current installation. After the new installation is finished, you can just copy any files you want from within the C:\Windows.old back into the new installation. Afterwards, you could delete the C:\Windows.old
folder to regain the hdd space. You will still have to reinstall all programs and drivers