Ok, I am explaining it in detail for your help:
1. first of all press ctrl+alt+del to open task manager.Click on the process tab and in the process list navigate for the amvo.exe. Then click on "end process" button.
this will kill the amvo.exe process.
2. Goto msconfig as previously. click on startup tab.
uncheck the amvo.exe> apply>ok
Dont restart.
3. Open registry editor by typing regedit on run. Click on Edit menu> find...>in the find what write amvo.exe>Click on find next button.
delete all the entries related with your find. repeat this step until the registry editor will not give the message: "finished searching through the registry".
(Do it be carefully). And if you feel uncomfortable here you can use Hijack this & CCleaner.
4. Now goto control pannel>folder options>view tab>Choose the option "show hedden files and folders".
Also uncheck :
1. "Hide extensions for known file types"
2. "Hide protected Operating system files"
(Reasion: Showing superhidden files).
5. Goto windows\system32 and delete the following:
1. amvo.exe
2. amvo0.dll
3. amvo1.dll
6. Also open your each drives and delete autorun.inf file which puts by these trojans.
7. Now restart your system. After restart set folder option and checkboxes as previous.
Note: Actually amvo.exe effect onto the Yahoo Messenger. if your system is infected by amvo.exe, than as you will try to run yahoo messenger it will crash.
In the Last if you think it so complex, then download "amvo cleaner":
www.ziddu.com/download.php?uid=bKqgnJamZLKglpSlsayZlJyiY66WlJyr3