These are a trojan/virus (either the Win32/Pacex virus or the Win32/PSW.Agent.NDP trojan) that uses those two files. avpo.exe, avp0.dll, avp0.exe, ntde1ect.com, autorun.inf, wscript.exe
Here is how you can get rid of them using command prompt.
1) Open up Task Manager (Ctrl-Alt-Del)
2) If wscript.exe is running, end it.
3) If explorer.exe is running, end it.
4) Open up File | New Task (Run) in the Task manager
5) Run cmd
6) Run the following command on all your drives by replacing c: with other drives in turn (note: if you have autorun.inf files that you think you need to backup, do so now):
del c:autorun.* /f /a /s /q
7) Go to your WindowsSystem32 directory by typing cd c:windowssystem32
8) Type dir /a avp*.*
9) If you see any files names avp0.dll or avpo.exe or avp0.exe, use the following commands to delete each of them:
attrib -r -s -h avpo.exe
10) Use the Task Managers Run command to fire up regedit
11) Navigate to HKEY_CURRENT_USER SOFTWARE Microsoft Windows CurrentVersion Run (as usual, take a backup of your registry before touching it!)
12) If there are any entries for avpo.exe, delete them.
13) Do a complete search of your registry for ntde1ect.com and delete any entries you find.
14) Restart your computer.