Windows 7 - Wireless USB will not install

I recently got cable internet service with a wireless router. Two of my computers worked ok but the cable installer could not get the wireless USB adaptor to work in my main desktop. The computer doesn't see the USB card at all. It is running Windows 7 home premium which is an up grade from Vista. Since then, I have purchased 2 more USB adaptors of different brand names and they all give the same problem. After running the install disk the software gets to the point where it asks you to plug in the USB card and then gives the message 'Error installing USB Device' and stops. I have also dowloaded drivers from the manufactures with no results. Any ideas?

Upgrade installs can sometimes be problematic, it sounds like the upgrade install has somehow messed up your installation of Windows 7 which is fairly typical.

You might try doing a clean install to see if it allows you to install the drivers for your USB adaptor.
Clean Install Windows 7

It's usually better to set up those wireless USB adaptors using the Windows 7 wireless connection manager.
Setting up a wireless network

Thanks for everything. I followed the 'Repair Windows 7 Install' procedure and it fixed my problem with wireless networking. 'Also fixed a long standing problem I've had with IE8 that prevented me from logging on to my bank's website. I had to use Mozilla up untill now. The minor problems I had were that Microsoft said my software was not legal at first and my background is black. I reintered my code 3 times and Microsoft finally accepted it.