can i run dj2 and dj3 on my pc at the same time???????
 

can i if so how?it keeps overwriting the other?can i flip flop and use 1 1 day and 1 the other day??

You mean can you have both installed on your pc at the same time??
No. Why would you want to? Either one will work fine. Well If 3.X works
for you then use it. If not then use 2.X. They both work for DC backups.