i guess Poser 5-6-7-&8 are 32 bit apps only.  Will they run normally on a 64 bit windows 7 os?

I am confused on this issue as no mention of 32 bit or 64 bit on Poser 5-6-7-8.  Poser Pro is advertised as 64 bit engine.  Will I have to get Poser Pro if i run a 64 bit os?

thanks for any advice.
Pappy