|When's the last time you dumped temp files & internet garbage? Do you have a cleaning program installed? If not, download & install CCleaner-Slim & use it regularly:|
And make sure you empty the Recycle Bin...all the files in it take up space until you empty it.
Have you uninstalled any programs that you no longer use? I'm sure you must have a few. And how much do you have stored in your My Documents folder? Right click on it, click Properties, then click the General tab...what's listed for "size on disk"? How about moving the My Documents folder to the slave drive?