You have a virus infection, u need a bootdisk from Avira called rescue system to be found on their site google avira  rescue cd  and dowload from site and burn to  cd, then boot cd  this will scan and repair your system, you must tick the boxes, repair files  rename files, this renames any and all virus's found, when scan completed   remove cd and reboot, you should now be able to access net and download malwarebytes antimalware, update this and scan  and keep scanning  it cud take several scans to clean ur system.
you will need a freind to obtain the boot cd file as ur unable to connect to net urself.
                
 Bob Macdonald
                
 March 2010