What is the make and model of camera? How long have you had the camera? Have you tried installing the latest drivers for camera? Check your system for any Virus's, malware, spyware, adware as these can corrupt software and the registry.
The camera is an Edimax EC-1510 I think! I should explain that this not my camera but is located in the living room of my aged old Mum. We use it to watch over her in case she takes a fall on her zimmer frame.So I just log on to the camera via its IP address which had been OK up until now. No camera software on my computer.I have AVG virus checker which I have run and all is OK in that respect.The rest of my brothers can log on to this camera no problem so the fault is with me. I'm the only one using W7 though interestingly!