Please try this first.
Dav555 very kindly provided this fix:
you should fixed the following problems with HijackThis
F0 - system.ini: Shell=Explorer.exe winsock.scr
F2 - REG:system.ini: Shell=Explorer.exe winsock.scr
O4 - HKLM\..\Run: [dxset.exe] C:\WINDOWS\dxsetu.exethen delete the following files with GiPo@FileUtilities (Move on boot)
(Remember to go into explorer, folder options, view and uncheck "hide protected operating system files" otherwise you'll spend forever and a day looking for things that aren't showing themselves, like I did!!!!!)c:\windows\system32\winsock.dll
c:\windows\winsock.scr
c:\windows\dxsetu.exe
c:\windows\system32\winlog.com
c:\windows\system32\dxwinex.exeI think these locations are right, the above files are either in c:\windows or c:\windows\system32
Reboot, then do a full system scan with your anti-virus program, this will pick up all the affected files and should delete\quarantine them.
Download moveonboot from here & the file(s) you choose will be deleted on reboot.
MoveOnBoot allows you to copy, move or delete files on the next system boot. This comes in very handy, if you need to replace or delete files which are locked by other applications, loaded into memory or cannot be changed until next system boot. You could manually enter a line to the wininit files, but using MoveOnBoot is much simpler, since the program can be integrated into shell - it creates the "Copy/Move/Delete on boot" context menu item.