After tinkering with the Windows 7 built-in backup, it appears that it will always run out of space, no matter what you do. It seems that Windows 7 backup keeps periods (full backup sets including a full backup and all incremental changes) indefinitely. No matter the size of your drive, backup will eventually run out of room causing the info bubble to appear in the lower right corner of the screen “Yer backup is failing ’cause yer outta disk space” or something similar. You just have to click the balloon, mange your disk space, and erase a couple of older periods. . . . This seems a little strange. Lets just tell it to only keep 3 periods. . .