Help! win32.trojan.rx has infected my computer.?

I have Windows XP and recently I started getting command prompt pop-ups, the computer was running slow, the internet windows started shutting down by themselves, a red ''X'' within a red circle appeared at the bottom right of the task bar, my task manager has been locked, my background has turned red. I ran hijackthis and this is what I got:

Logfile of Trend Micro HijackThis v2.0.0 (BETA)

Scan saved at 7:30:37 PM, on 6/4/2003

Platform: Windows XP SP1 (WinNT 5.01.2600)

Boot mode: Safe mode with network support

Running processes:

C:\WINDOWS\System32\smss.exe

C:\WINDOWS\system32\winlogon.exe

C:\WINDOWS\system32\services.exe

C:\WINDOWS\system32\lsass.exe

C:\WINDOWS\system32\svchost.exe

C:\WINDOWS\System32\svchost.exe

C:\WINDOWS\Explorer.EXE

C:\PROGRA~1\Yahoo!\browser\ybrowser.ex...

C:\PROGRA~1\Yahoo!\browser\ycommon.exe

C:\Program Files\Yahoo!\browser\ybrwicon.exe

C:\PROGRA~1\Yahoo!\MESSEN~1\YAHOOM~1.E...

C:\WINDOWS\system32\services.exe

C:\WINDOWS\TEMP\7238.tmp

C:\PROGRA~1\Yahoo!\browser\ybrowser.ex...

C:\Documents and Settings\Owner\Local Settings\Temporary Internet Files\Content.IE5\Q38BUFE9\HiJackThis_v2...

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Page_URL = http://us7.hpwis.com/

R1 - HKCU\Software\Microsoft\Internet Explorer\Main,Default_Search_URL = http://srch-us7.hpwis.com/