How can I remove a virus?

In my PC, upon opening the control panel add/remove program, it displays the page and after some seconds the page dissappears, some other pages behave that way too, Secondly, a new folder is created in any flash drive i insert into my PC and if i try to click this folder it duplicates itself,Recently I scanned the flash drive with McAfee Antivirus,it detected and deleted the viruses, after that these folders remained hidden yet occupying space in my flash drive,
I can't access them, Please help, I'll be grateful.
Thanks
Right now it had hidden all folders in my flash, but the capacity shows that the files are still there
Please can someone help me
Thank you