I have been using Windows Backup and Restore in Windows 7 for over three years. I create an image of C: each night and also do a file backup of D: each night. This process is automated and has worked flawlessly for me. I do not want to change to another backup system. Yesterday, when I checked my backup, I saw an error message: Check your backup/ Invalid window handle, / Error Code: 0x80070578 Upon analysis, I found that the Image backup worked just fine. The File backup stopped exactly at 25% complete. I tried changing the backup destination to a different external drive. I tried running the backup as a different user. I tried significantly reducing the number of files to be backed up. I tried using msconfig.exe to boot into Selective Startup mode. I ran sfc/scannow. I ran chkdsk. None of these helped. I also did a somewhat extensive search of Google. I found a number of queries about the same problem but no real answers. The Microsoft help responses didn't even seem to recognize the problem and provided canned answers to "similar" problems with different error codes. I realize that I have numerous alternatives and have already temporarily implemented EASUS TODO for file backup. What I am looking for is an explanation of this cryptic error message and some information leading to a solution. Thanks in advance for any help and advice.