David's hard drive is filled and he used WinDirStat to see what's filling it up. He sees that there's 25GB of "installer" files. Can he get rid of those? Leo says he suspects that those files are hot fixes for Windows and he can't really delete them because it could make his system vulnerable. Leo suggests running Windows' Disk Cleanup Utility. It's not too aggressive and will clean out temp files, download files, etc. Just press the Windows key and type "Disk." Another thing to look for is previous Windows installations.