I know there's a virus but i can't detect it. Help?

Why not register and post your question at the Avast forums ?

http://forum.avast.com/index.php?board=2.0

All you are likely to get here are guesses and "advice" to change your AV.

Alright so all this method depends on is when you got this problem. Go to start-all programs-accesories then system restore or find something like that on your computer. Restore your computer to a day you know that you didn't have the virus. Once you have restored your system download malywarebytes. If you get a pop up saying "your browser is under threat of infection. Windows requires your permission to install online protection tool." alright so don't allow anything like that. Hope i helped you.

Hi

The best thing to do is back up your data onto an external hard drive and take the laptop back to manufacturers settings and then reload everything back onto your laptop. once you have done that run a boot scan with avast and also try trends micro house call that should pick any viruses lurking in your laptop.

Do a quick scan with Malwarebytes its very effective and free, if you cant or it doesn't remove it try Hitman Pro it scans with five different anti-virus engines at once, simply activate the 30 day free trial then once you PC has been cleaned remove it.

http://www.malwarebytes.com/

http://www.surfright.nl/en/hitmanpro

Please email me and let me know if it worked, thanks :)

Maybe Avast is failing you for once, or you could update it and try scan again.