can’t get picture from webcam

I wonder do i have a motherboard problem? I’ve installed 3 USB webcams so far on a computer using Windows 98SE and so far didn’t get a pic on screen with any of them. I tried the cams on other computers and they worked. One tells me that it can’t open the camera and should it force it, of course, i answer yes, but to no avail. I can’t access the camera settings because they are greyed out. The other cams, gives me the error that it can’t save the picture to C drive to a folder in My Documents. I know that as soon as i open the software and click on the right settings a pic should show, but NOT. I am at a lost here. Got any ideas? Thanks