Access is denied

Symptoms:

When clicking on the vsto install link

Answer

1. Log on to the pc as an administrator

2. Locate the file UsrClass.dat  in C:\Documents and Settings\user\Local Settings\Application Data\Microsoft\Windows

3. Rename the file UsrClass.dat to UsrClassOld.dat (effectively deleting but with a backup)

4. Log on with your usual username.

5. Try the MerlinXL installation again