You may need to register the VBscript again:
1. In the Start menu, type cmd in the Start Search field.
2. Right-click on cmd in the list of search results and click Run as administrator in the pop-up menu. If Windows needs your permission to continue, click Continue. (If you are not logged in as an administrator, you will need to authenticate with an administrator login and password.)
3. In the Command Prompt window, enter the following command:
4. Press Enter on the keyboard. A message should appear stating: "DllRegisterServer in vbscript.dll succeeded."
Note: If you see a message with "error code 0x80004005", the command window was not opened as an administrator.
5. Click OK and try installing iTunes or QuickTime again.
Hereâ€™s to Good Karma