Hard drive says its full but I've deleted most files?

Have you emptied the recycle bin after you deleted the files? Deleting often only moves files to the recycle bin rather than removing them.

You could also try deleting old system restore points as they can take up a lot of space.

The other option is checking the page file as that is well hidden and can take up tons of space if your not careful.

whats the page file?

The page file is part of the hard drive that windows treats as RAM (sort of). Left to its own devices windows can make this file the same size or even double the amount of RAM you have. Because the system will crash almost instantly if you mess with the file windows hides it from you.

I would install something like this http://windirstat.info/

It will give you a graphical representation or where your space has gone. If you are using a Mac use GrandPerspective instead.

I second @johnpowell‘s recommendation for WinDirStat. It gives a nice, graphical representation of how much space things take, and it isn’t fooled by things like files buried 9 directives deep with the “Hidden” attribute set.

Thanks johnpowell! Neat program.