Can't stop process in Windows 7

[laddie]

· Toshiba Satellite Laptop
· 2 Gig duel core processor
· 4 Gig of memory
· Windows 7 Home Premium 64 bit
· ATI RADION HD3650/W 512 mb
Hoster 4.11

Let’s start by saying that I don’t think this is a problem with Hoster, but it is causing me problems with Hoster. When purchased, this machine had Vista. I ran Hoster and Traktor on the same machine with almost no problems, then for some reason I decided to upgrade to W7. That’s when the problem started.
Once or twice a night Hoster stops responding and just hangs. When this happens I try to use task manager to end Hoster, doesn’t work. I have tried to use PSKILL to end the process, doesn’t work. The only way I can clear Hoster is to reboot. Of course this takes a lot more time than simply ending the process and reopening Hoster.
Has anyone experienced this with Hoster or any other programs in Windows 7? Anyone with any ideas on a fix?
Thanks in advance