This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator.

Users are unable to open url links in Outlook 2007/2010 and get the following error message: This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator.

Fix

1. On Windows 7 and Windows 8, click the Start button, type Regedit and hit Enter to open the Registry Editor. On Windows XP, click Start > Run and then type Regedit in the Open box.
2. The Registry Editor will open, and you browse to HKEY_CURRENT_USER\Software\Classes\.html. Verify that the Default value of this key is htmlfile.
3. If the Default value is ChromeHTML or FireFoxHTML (depending on which browser you have installed), right click it and select Modify…
4. Change the Default value to htmlfile.
5. Repeat steps 3 and 4 for .htm and .shtml keys.
6. Restart your computer for the changes to take effect.