Using a ps2 mouse with windows vista.

[Ric]

I was wondering if anyone can help me with a problem I am having. I am using a laptop with only usb ports and windows vista installed. I have a mouse I want to use with the laptop but it has a ps2 plug on it. I have a ps2 to usb adapter connected to it and it comes up as an unknown device. The mouse is an old style, ball/roller, dell.

I have tried microsoft and dell websites in vain. Any suggestions?