Windows 7: Computer won't recognize phones via USB

I originally posted here:
http://www.sevenforums.com/general-d...ml#post1243026

Mods, please merge or delete the above thread.

Problem:
For some reason, my computer is not able to connect to phones using usb. It started about a year ago when iTunes would not recognize my iPhone half the time. I thought my phone was faulty because I had dropped it, and ignored the problem. But I recently got a new phone, Samsung Focus with WP7, and I am not able to connect it to Zune player to add/remove songs. It worked the very first time i connected it, but since then it has not. I also tried another phone (Pantech Laser) and it did the same thing; worked the very first time I connected, was able to transfer files, but after that, it didn't work.
The phones charge when connected, but the computer does not recognize it as a phone, or at all for that matter. And they work fine when I connect them to my netbook, so its not the phones or the cables.

When i connect the phone, Zune player does open up, so I assume it sees it as a phone initially. But Zune says no device connected. Similar problem happened with my iPhone n iTunes, the program started when I connected, but unable to actually recognize the phone.



All other USB devices function normally (flash drive, hard drive, printer, keyboard/mouse).

Ive tried all the ports, front and back, and get the same problem.

Any specific settings I can check for phones not working?

Thanks for any help.