click here download and run to clear all the temp files. Then download Sunbelt counterspy click here it is a free trial and you only have to give your email addy. Run it and delete all it finds. Start up in safe mode and delete bla.exe if it is still there.
You can delete all the files in the AVG vault.
AVs will not always stop Trojans, if you unwittingly execute the programme no amount of firewalls and AVs will stop it. Sunbelt does provide 'real-time' protection though and it is free for a month or so. Worth paying for IMHO as it is virtually the same as MS Antispy but it can run on other OS's than just XP. MS Antispy will only run on XP.