Some tips to free space on the main drive. Set I.E temp files to 100mb or even less. Change Recycle Bin reserved space (usualy 10% by default), if you are fairly confident you don't need to revert to any old versions of patches, go into C:\Windows and delete all the files that start with $NtUninstall. Those are files patches keep for backup if you even need to uninstall them. In the many years I worked with computers, I think I needed to uninstall a patch maybe twice, so it's pretty safe to delete these. You can also move your My Documents to the other drive. Right-click on My Documents, select the new folder to move the contents to. Since your 120gig drive is probably a few years old, you may want to get an external drive for backups incase the drive failes.