You may receive an "INF Install Failure. Reason: Access is Denied" error message when you try to install Exchange Instant Messaging Client 4.6 on a Windows client computer

When you try to install Microsoft Exchange Instant Messaging Client 4.6 on a Microsoft Windows-based client computer, you may receive the following error message:

To resolve this problem, follow these steps.

Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

Note Because there are several versions of Microsoft Windows, the following steps may be different on your computer. If they are, see your product documentation to complete these steps.

1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\Migration DLLs
4. On the Edit menu, click Permissions.
5. In the Group or user names list, click Administrator. If you do not see Administrator in the Group or user names list, add it to the Group or user names list. To do this, follow these steps:
   1. In the Permissions for Migration DLLs dialog box, click Add.
   2. In the Select Users or Groups box, click Advanced, and then click Find Now.
   3. In the list box, click Administrator, and then click OK.
   4. Click OK.
6. In the Permissions for Administrator box, click to select the Full Control check box under the Allow column.
7. Click OK.
8. Close Registry Editor, and then try to install the Exchange Instant Messaging Client 4.6 again.