I have had something like this before, definately go the Aida route as btcastner suggested, it really is a good bit of software
The only problem I could think of is that Aida may not say exactly what the Modem is (Or miss report it), if it doesn't get it right it really would be easier to hook out that PC, get the side of the case off and look on the modem for numbers\model name or number and possibly manufacturer
If getting the side of the case puts the fear of god into you, theres not too much to worry about, just be brave and do the following...
- Pull the power cord from the PC power supply (Extermely important)
- Disconnect cables if you like (Keyboards, mice etc)
- Make sure you ground yourself to get rid of any static
- Unscrew case
I really can't see that you would damage anything since you will only be "Looking" at the details on the modem card and shouldnt really be putting your hands in there dabbling!!
Make sure you have a suitable area to open the PC case such as a table or worktop
When you got the numbers then you can find manufacturer and get the latest drivers
Good luck
Jamie