[ShockTroop]

I'm having an odd problem with internet connection. I'm using Windows XP v5.1 Build 2600.xpsp1.020828-1920 : Service Pack 1. I don't think the hardware specs would help, but let me know if I need to specify anything. I use a firewall but am not sure what software it is. My server is NCIA and I have Norton Antivirus 2003 up-to-date in virus definitions.
Before any of this happened, while visiting a site about 2-3 days ago (the name slips my mind), I was asked if I wanted to download something by Tempo Interactive or something like that. I said no, but when I visited any other site, in the status bar on the bottom of the screen it said something like "installing cbein.cab..." (I'm not sure if the name's even close to what it was). After not being able to load the site without "installing," I let it do its thing. Now when I go to any given site, a popup ad appears, even if it's a site such as Google that normally doesn't have popups.
Here comes the wierd part. The current connection to my server (NCIA) seemed to become "corrupted." When I clicked on the IE icon, normally it would automatically dial up. Now the home page loads up automatically whether I'm online or not, and I have to direct to a different site to get it to connect. I checked all the internet settings, and they're all fine. One thing did have to be changed, though. When I re-directed to another site, the MSN Explorer login screen popped up as if it was triggered to do so. Anytime I wanted to sign in to MSN Explorer, when I clicked Sign In, it acted as if I clicked Cancel immediately after, bringing me back as if I had just opened MSN Explorer login. After searching through the settings, I noticed that MSN seemed to have a separate dial-up to a totally different server, but it didn't specify what. This was probably why it popped up.
I was forced to make a new connection to the same server. A few minutes after doing so, I was offline when it said the new connection was offline, but the old connection was online. I'm positive I didn't go online or anything, and the icon in the taskbar wasn't there. It was as if it auto-dialed to a separate server without notifying me.
I've had to make another new connection since then, making a grand total of 3 connections to the same server. The thing where the home page loads up automatically and I have to re-direct to a different site to dial up still occurs, but other than that, it's been acting normal for the last few hours. I'm pretty frustrated as to what's going on. I've run Norton, and it didn't find anything (I updated it last night), and I've also run Lavasoft's Ad-Aware v6.0, and it found a couple things that I got rid of (it found one called Alexa in the registry, but I didn't delete it). I'm not sure if running Scandisk/Defrag would help, but any help would be appreciated.