first of all, try to create a folder named autorun.inf in every drive. For this delete the autorun.inf file and immediately create a new folder with that name. If you are not fast enough, the file will reappear. So you can create a batch file. For this open notepad type
del /f autorun.inf
md autorun.inf
save this as xyz.bat. now copy this into the drive and double click on it. I this succeeds, it will be easier for you to remove the virus.
After this, remove any unwanted and suspicious startup entries or boot into safe mode. Now open task manager and stop any suspicious Process. to know what a process is you can got to
www.processlibrary.com
install prio and stop any services related to any process which are suspicious. prio enables you to go to an associated service by right clicking on the process in task manager. In case task manager is not opening, you can download yet another process manager to do the same thing.
Finally, download the trial version of ESET NOD32 antivirus and scan your computer.