trojan questions

ok...last week, i found a trojan on my pc. thankfully I caught it as soon as I got it. it was in a .rar file. i deleted the contents of the .rar, including the trojan, but forgot about the .rar file until yesterday. now, did i screw myself by not deleting the .rar file until later? is there a program that can tell me if a computer has blocked or that has access to my pc? I have ZA installed, but my internet connection has been acting up on my since yesterday, and I didn't know if it was the trojan or not. I've ran The Cleaner and AVG, and I'm clean.

My internet problems are this: The IP address that I've been using for sometime now, no longer works past our DHCP server. I can log into that server, and I can access our whole network. But I can no longer "get out" of our network. ZA shows its working properly, and the correct programs have access out. Even if I shutdown ZA, I still can't get out. I had to give myself a different IP just to access the net. This started yesterday around the same time as when I deleted the above .rar containing the trojan.

I'm at a loss as to why my pc won't let me out w/ my previous settings.

 

try uninstalling and reinstalling your TCP/IP stack.

 

won't let me...its greyed out. i'm using xp. is there another way to do it?

 

uninstall your NIC and reinstall it.

 

that didn't work either. its the oddest thing. i'm the network admin, we don't have a proxy server (well, our static IP's have unlimited access...and I have a static IP), I can see everything on the network, I just can't get out of our network. Its like something is blocking my original IP. When I change it, then everything is peachy.

 

are you blocking a range of IP's on your router or something?

 

nope. we have a content filter box that runs our DHCP. the range for dynamic ip is x.x.1.11-x.x.1.230. all other ip's (x.x.1.2-1.10 and x.x.1.231-1.253) bypass our content box, giving them unlimited access out of our network. now, after we set everything up, I took x.x.1.231, giving me unlimited access. Everything was working marvelously until yesterday. now if I change my ip to x.x.1.231, I can access both of our servers, as well as the content box, but I can't get past the box. so I changed my ip to x.x.1.4, and I'm getting out again. I didn't change any DHCP settings on the box, so I'm confused on why all of a sudden that specific ip won't work, and I didn't know if it had anything to do with the trojan I received and deleted.

btw...thanks for the help.