Webcam issue

Hi,
Trying to install a Microsoft Webcam VX-3000 (new) on my Windows 7 Ultimate machine. The PC is an Intel dual-core with 4G RAM. The installation CD downloads the latest driver for Windows 7, and everything proceeds smoothly until it asks me to plug in the camera. After plugging it in, the installation tells me the camera can't be found. In addition, the "on" LED on the camera remains unlit. Some observations :

1) The very same webcam installs perfectly on a friend's machine running exactly the same OS and similar hardware.
2) The USB port seems to be working fine - Device Manager reports it is working properly and other USB devices (memory sticks, printers) work fine.
3) Trying to install on other USB ports result in the same failure.

I really don't know what is going on. Any thoughts would be welcome ...
Thanks,
Carl.

Many thanks. Appreciate the rapid response. - I will try your suggestions as soon as I wrestle my webcam back from my friend.
I used Device Manager to look at the status of the USB ports. As stated, it reported "this device is working properly" and no yellow triangles.
If all of the above fails, could my chipset drivers be suspect?
I ask this because my PC has been upgraded from XP to 7 a few months ago (which went very smoothly). All other USB devices are working well.
Cheers,
Carl.

My roommate has the same camera (or at least, it's one of the VX-xxxx series). It was a nuisance and a half to get it working for her.

Did it make you install Windows Live Messenger? We got nowhere until that was set up.

Really appreciate the help ...
Well, I tried all the above - no joy.
Windows "sees" and recognizes the webcam - even displays an icon! The drivers fail though, despite the driver install reporting a successful install. Yellow exclamation marks everywhere. Device Manager reports "unable to start this device because registry information is incomplete or damaged".
Did not install Windows Live Messenger because the installation routine had failed to detect the camera before that point in the installation.
Totally confused ...

Cheers,
Carl

carl4 said:

...Did not install Windows Live Messenger because the installation routine had failed to detect the camera before that point in the installation...

Just to be sure, which installation are you referring to here? The Windows Live Messenger, or the camera software and drivers?

The installation disk (and instructions) first installs the camera software and drivers, then asks you to plug the camera into a usb port (which I did - although the activity led on the camera remained off). Clicking the "next" button in the installation causes the camera software to open a window which, in my case, displays "there is no camera attached to this computer". If you ignore this, and click on the second "next" button, the installation process automatically starts installing Windows Live Messenger - despite the fact the camera had failed. I aborted the installation as this last step commenced figuring what is the point if the drivers aren't working..

Sorry - I should also have pointed out that Windows 7 thinks the drivers are just fine. An attempt to "fix" the problem by having Windows download the latest drivers always results in a message informing that the installed drivers are up to date. An earlier post details what Device Manager reports.

Carl.