My Win 7 installation originally allowed the 'run as' operation. Recently I needed to replace a system file and so required the 'run as administrator' to use "sfc /scannow". It was no longer available; either by right-clicking file name etc or using <ctrl>+<shift>+Enter. I have done the obvious things with UAC. Nothing seems to work. Is it possible to edit the registry to enable this command to work? BTW in all other respects my installation is in first class condition, fast, stable, responsive. My only problem is that the backup utility in Control Panel can't find sdclt.exe file to run backup.

Hi, System Restore can be your first option since it worked before. Moreover, you could test other user accounts to see if the issue occurs. If the issue doesn’t occur, the user profile is corrupt, you may need to fix the corrupted user profile. If the issue occurs with other user accounts, I am assuming that there might be system files corrupt. I recommend you to perform an In-place upgrade. In-place Upgrade is a special upgrade process to repair the system. In-place Upgrade will not affect settings like photos, movies, documents, etc. that are saved on the computer. 1.Perform a clean boot in the current operating system. 2.Insert the Windows 7 Installation Disc to your DVD-ROM drive. If AutoPlay pops up, click “Run setup.exe” directly. 3.Click “Install now” on the “Install Windows” screen. 4.In the “Get important updates for installation” screen, it is recommended to select the first option to download latest updates for installation, if Internet access is available. 5.Check the box “I accept the license terms” to agree with the installation license and click “Next”. 6.In the “Which type of installation do you want?” screen, click “Upgrade” to perform the In-Place upgrade. 7.Then, follow the wizard to finish the In-place Upgrade process. Best Regards Dale Please remember to click Mark as Answer on the post that helps you.