Win32:Vidlo-H [Trj]

Avast has identified this trojan and supposedly moved it to the chest. It continues to reappear.

What do I need to do to get rid of it?

Can you post more info?
Operational system?
Firewall?
Which is the infected file and path name?

Things don’t just reappear you are being reinfected and it could well be another element/file that restores the file or continuing to visit the same sites or you still have a vulnerability that hasn’t been closed.

Besides answering what Tech has asked do you have any other security software?

Also useful as a diagnostic tool - Download HiJackThis.zip - HJT Information HiJackThis Tutorial 1 or HiJackThis Tutorial 2
For an on-line analysis - HiJackThis Log file - On-line Analysis
Ignore any 023 reference to avast processes, this is a hiccup in the HJT 1.99.1 (especially missing file entry for avast), if you need any help with any of the analysis let us know.
OR HiJackThis Log file - On-line Analysis 2