WinXP SP2 won't let me connect

[Rakinite]

Windows Version (and Service Packs): Windows XP Professional
Processor Speed: 2000 Mhz
RAM: 768 MB
Hard Drive Format: FAT32
Video Card (Make and Model#): Nvidia GeForce FX 5500
Sound Card (Make and Model#): VIA AC'97(Some generic motherboard card I think)
Connection Type (Dialup, Cable, DSL, other): DSL
Modem (Make and Model#): ?
Router (Make and Model#): Belkin USB Ethernet Adapter
Internet Service Provider(company name): Zoomtown
Location(State/Province/Locality, and Country): Cincinnati, OH, USA

And after that...
Anyways, I recently upgraded my computer from old faithful 98SE to a nice copy of Windows XP Professional. The problem is that supposedly Allegiance has problems with XP unless you install the Service Packs. Unfortunately, when I downloaded SP2 onto my system, its security features basically blocked off my internet access almost completely. For some reason, I was able to play "Subspace Continuum" online, but I'm not sure why. Windows' firewall, autoupdates, basically all the security features that were there are off...

I'm not going to re-install SP2 until I find out how to avoid the connection blockage... has anyone had this kind of problem before, and if so, how did they fix it?

[Grimmwolf_GB]

It is usually the firewall, that turns itself on again. Install SP2, it is critical. Find the firewall for your connection and disable it.