PC based CCTV DVR looking for software

I have built a PC Based DVR for security camera's. I'm looking for some good DVR software. The camera's are fixed. It seems like a lot of the software out there is tied to the board. Does anyone have any recomendations for software. Right now I am using Digital Video Witness that came with my PCI DVR board. It's OK, but I don't like that if you close it, it turns the PC off. The software doesn't need to be a web server because I can just use WinVNC. Thanks Brian