Using 2.2 and 2.3 together

[Ken]

Hi. How can I run 2.2 and 2.3 together without them interfering?

I have installed them to different folders in C:\Program Files.  But
when I load them they seem to use the same start-up settings (i.e.
last file).  If I open file A in 2.2.  And then I open file B in 2.3.
When I go back to 2.2 it will try to open B.  Is there a way to force
2.2 and 2.3 to use different settings locations within my user
profile?

I ask b/c I want to test 2.3 but still do my own accounting in 2.2.
If the last account used in 2.3 was a MySQL account, then this causes
an error when loading 2.2.

Thanks,
Ken