" I have an alcatel USB ADSL modem. After I installed Linux, winxp would detect new hardware and try to reinstall my modem each time I booted winxp. I would reinstall, and the next time I got back on winxp it would find new hardware and try to reinstall my modem as if it kept losing it. I am not sure why this happened. I ended up having to uninstall Linux so I could work."
I would first assume that you don't have a router?
Second - I would get one for your protection- (A nice little firewall helps a little).( NOT a total soluton but keeps things a littel safer for you.) You also can have additonal computers connected to your network as well and have just one connection to the ISP. !!!!
If you do this and get everything setup in XP- then install Mandy and run it under DHCP _ your router can and will handle this for you just follow the directions.
Strange that XP losses it Modem after reboot from Mandy- did you download service pack 1? cause if you did you agreed to let M$ look on your computer at anytime they feel like there is pirated software on it-
and disble your machine- who knows if they can tweak it if they think you have Linux on it as well. ( Far Fetch I know but read the EULA for yourself and decide for yourself if you want to subject your computer to them?)
Good Luck with Linux,