"I think I found the solution for this problem. I hope this works for everyone else also.
So I installed the PC Studio 3.2 and also made a full live update for it. It could not find my SGH-U800b. After swapping the USB-slots on the computer I realized that it had some kind of device error. So I opened the windows 7 device manager and there it was Samsung Mobile Modem with exclamation mark. It could not find the drivers I just had installed. There was a quite simple way to remove this and make the whole program function. Right click and press "properties" -> "driver" -tab -> "update driver..." -> select the "Browse my computer for driver software" -option -> now locate the Samsung Pc studio folder and select that exact folder, if you scan the whole computer it can't find the drivers!!! And now this should remove the exclamation mark and now you can connect to the phone. I also have the Windows XP (sp 3) compatibility mode on. But I'm not sure if it's necessary.
As you mentioned that using previous versions of windows operating system namely xp and vista you were successful to use and install pc suite,the same version is not compatible to windows 7.You will have to update or download the latest version compatible to your actual operating system.Use link below from official Samsung website and download latest compatible version:
Have just had the same problem and after speaking with someone form Samsung, I was told that Samsung currently have no driver available for windows 7. There is one currently in development but he was unable to give me a timeline. The only thing you can do it wait and check Samsung periodically to see if the new version is ready! This really sux!