Upon installation of Windows 7 check that your drives are visable by Disk Manager, if not you will have problems as time passes, most notable is the inability to do disk fragmentation either by the built in defragmenter or by programs such as Perfect Disk. The operating System will perform like everything is normal but it is broke. This can be checked by: 1. Opening the Start Menu and right clicking on Computer and select Manage. 2. When the Manager opens select "Disk Management" and you should see "Connecting to Virtual Disk Service" and then the drive information should be displayed. If it hangs on "Connecting to Virtual Disk Service" and does not display your drives you have a broken operating system. Not sure if their is a MS hotfix or not but a reinstallation of Windows 7 fixed the problem on the two machines I have seen. BTW.. FWIW. Both machines were original loaded from a USB stick. and reloaded with the DVD.