Malware Removal - Trojan Horse Sheur2 Infection - Please Help!

Hello! I am new to the Majorgeeks community and would like to introduce myself by pleading for your help in order to remove a pesky Trojan Horse Sheur2 infection. I hope you can help me!

Type - Windows XP Version 2002 Service Pack 3

A week ago, I was infected by a virus that had entered my computer through the backdoor and completely ****cked my computer. My computer began to get start-ups that would promote fake anti virus programs, slowed down my computer, and disabled and removed the System Restore tab (so I cannot turn on system restore anymore). When I noticed something was wrong with my computer, I hastily tried to run AVG, Spybot, and Malware-Bytes to rid my computer of this evil malware, but none of them would run (obviously blocked by the virus). I attempted to reinstall and install new anti virus programs, but none of them would ever work.

Finally, my computer was completely struck down. It shut off by itself, and I was left with a blank screen. I tried to reboot my computer, but the virus would always stop me from logging in my account by freezing me whenever I reached the 'Welcome' screen. It cut off my internet connection in Safemode with networking.

As I began to think that my computer has officially surrendered to the evil virus, a miracle happened! My AVG actually successfully opened in Safemode and then ran itself a full virus scan. Apparently, the scan only detected name of the virus, Trojan Horse Sheur2, and only removed it temporarily. After the scan, I immediately restarted and my computer actually got through the Welcome screen and pulled through (not in Safemode).

....anddddd this is where I am now. I have cleaned temporary/internet files with the Disk Cleanup and read + completed the instructions on 'READ & RUN ME FIRST. Malware removal guide' (except the antivirus scanning portion, which I was not successful in). I have also removed the Viewpoint Media Player program that I found in Add/Remove Programs. I think this did little good, but the virus is still in tact, because I am still occasionally getting advertisements.

Please help provide an answer for me to rid myself of this evil virus. If you need any logs or information, please provide instructions and I will do it and post it here as instructed. I have read most of the pre-guided threads on this forum and still cannot come up with an answer. I am afraid that if I restart or shut down my computer, I will not be able to get through the 'Welcome' screen again.

If this has turned out to be the end of my poor, overused, cheap, and extremely aged computer; may this thread serve to be a lasting tribute for all of the times my computer has saved me from dying of boredom. R.I.P.

*Please Post to Help!*