Sorry, the new software is totally separated from your old Stripsaver/VG2 account. BUT if you have your old login information you can still access the old VG2 files and install the old software to run side by side with the "new".
http://members.virtuagirl2.com/Also, the team is working on reprocessing old cards from VG2 as Classics but you need to have at least 100 cards here on VGHD before you can buy these (yes you need to pay for them one more time to get them integrated with the new version).
Edit:
Just set the software as your screensaver and select "Always start disabled" from the Advanced setting. (see image)