TROJAN.WIN32.CP4000 affecting XP

I have a Dell Inspiron 6400 with Windows XP and I am having trouble getting the darned thing to work properly. First, the system will not reboot properly. On the desktop I don't have my usual desktop toolbar at the bottom of the page with my shortcuts like OpenOffice, Skype, SpyHunter and it appears in a thin grey box. Everytime I reboot I get two messages. One says that Skype took a deep breath and is having difficulties and will need to shut down. I was using Skype when I started having the problems. Second, a message reads something like notification dll cannot access wireless internet connection. Very true since I cannot access the Web on my computer now in any way. The browsers all say that the Internet is not hooked up.
I have tried to run Skype, my VLC media player, Realplayer but nothing works at all. The programs just won't run. It's really wierd. I think my operating system has been corrupted by a virus I was exposed to called the Trojan.Win32.CP4000. However, I have been in correspondence with the guys over at AllExperts.com and they said all of my scans were clean.
What do you think is wrong? Has the virus somehow corrupted my OS startup protocols? If the computer is clean, how do I sort out the startup protocols?
My computer did not come with a Windows XP disk so I can do a Install repair but I am not very technologically savvy. Any advice would be greatly appreciated.
Thanks,
SEAN