Ran across this issue three different times; a user installs Adobe Reader update and Google Chrome gets installed. The user then uninstalls Chrome and when they try to access hyperlinks from any program, it fails. They would receive the error "This operation has been cancelled due to restrictions in effect on this computer. Please contact your system administrator."  Going in and changing default browser settings did not fix the problem. It requires registry changes to fix the default browser.

Restore registry settings in the User Profile: [more]

  1. Click Start, click Run, type Regedit in the Open box, and then click OK.
  2. Locate the following subkey:
  3. On the File menu, click Export.
  4. In the Export Registry File dialog box, enter HKCU_Classes_HTML_Backup.reg and click Save.
    Note: This will create a backup of this registry key in the My Documents folder by default.
  5. Right click the (Default) value for the .html key and select Modify...
  6. Change the value from "ChromeHTML" to "htmlfile"  (or from FireFoxHTML to htmlfile)

Repeat steps 1-6 for .htm .shtml .xhtm and .xhtml k

I have read that you can change the default browser prior to uninstalling and this will not be a problem. However I have not tested this.