Modem/network problem

Hi!
I use an USB modem. It works fine on this computer(win98) which I'm using now. But when I'm using it on my other computer(xp), the modem speaker makes unusual noises. And when connected to the net, any browser on that computer cannot find most of the web sites. This started to happen when I re-installed windows lately. I ran the troubleshooter but it can't solve the problem. Anyone know what's the reason for this?
Thanks.

did you install drivers for your modem
that were for xp? if they dont have drivers
sometimes 2k drivers will work.

did u try a different usb port? that fixed my old usb modem

Yes, I have installed drivers for XP, and I tried the other USB port. But it didn't work. Before I re-installed a newer version of XP it worked fine.

u recently update to sp2? if so turn off the firewall.