If you need to get the CLSID of an application do the following:
1) Start >> Run >> Regedit
2) Go to HKEY_LOCAL_MACHINE\SOFTWARE\CLASSES\CLSID
3) Within this branch hit ctrl + F to search for the application you require the CLSID for e.g. Excel
4) Hit F3 to go through the results until you find the application you need
Windows
excel