This may sound stupid but remove all the " and it should work
C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe –datadir=G:\Bitcoin
C:\Program Files (x86)\Litecoin\litecoin-qt.exe –datadir=G:\Litecoin
Tried that and windows 7 reports:
The name 'C:\Program' specified in the target box is not valid. Make sure the path and file name a correct.
So looks like it can't handle the spaces without the quotes. I also expanded the double quotes around the entire string and got a different error.
For some reason it does not raise any errors on:
C:\Program Files (x86)\Bitcoin\bitcoin-qt.exe \datadir=G:\Bitcoin
C:\Program Files (x86)\Litecoin\litecoin-qt.exe \datadir=G:\Litecoin
But still uses the same directories on C drive when loaded from the shortcut.