Prompted for CD-ROM When You Run System File Checker While Correct CD-ROM Is in Drive

When you run System File Checker (SFC), you may receive the following error message: Even if the correct CD-ROM is in the drive, you may receive a second error message:

This issue can occur if the computer security policy is set to allocate the CD-ROM only to the local logged-on user. However, Windows File Protection is controlled by the Winlogon process; when that policy is in in effect, Winlogon cannot use the CD-ROM and that prevents the System File Checker from completing successfully.

To resolve this issue, disable the security policy temporarily:

NOTE: You must restart your computer for the change to take effect.

1. Click Start, and click Run. In the Open box, type mmc, and then click OK.
2. On the Console menu, click Add/Remove Snap-in.
3. On the Standalone tab, click Add, and then click Group Policy in the Available Standalone Snap-ins list.
4. You may receive a message that the Group Policy Object applies to the local computer, click Finish, click Close, and then click OK.
5. In the MMC snap-in, view the following entry:
   Console Root\Local Computer Policy\Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options
6. Double-click the Restrict CD-ROM access to locally logged-on user only policy, click Disabled under Local Policy, and then click OK.
7. On the Console menu, click Exit, and then restart the computer.

This behavior is by design.

The system policy may be set back to the original setting after the System File Checker has completed the operation.