Halion 4 and Halion 3 on the same PC

Could somebody answer me the question, if I can have installed Halion 3 and Halion 4 on the same PC (Win7, 64bit) and use it in Cubase 7 (64bit) at the same time. It would help me temporarely to open projects made on former PC (WinXP) in Cubase 5 with Halion 3. Thanx

You can certainly have both on the computer at the same time and load which you need when needed without issue. I have that happening here as a matter of fact.