Win32:BitCoinMiner-CA Removal help

please help me, I have some problems with this trojan. I tried everything but Avast seems not to remove this virus, it keeps coming back after some minutes. Any help would be greatly appreciated, thanks.

Location: C:\Users\xxxxx\AppData\Local\Temp\iswizard
Infection: Win32:BitCoinMiner-CA (Trj)

http://i1351.photobucket.com/albums/p790/ryanex1/www_zpse602e65f.jpg

Please follow the steps here http://forum.avast.com/index.php?topic=53253.0