Virus problem of my computer-3 beeps on startup

Normally my computer have 2 short bleep sound when it start.. But now there is an another short bleeps between the 2 bleeps.. And when computer ready to work after all booting and other steps it seems very slow and sometimes the keyboard does not work.. may after sometime it will work properly.. And also sometimes computer automatically selecting the icons which is present in last of the window..
When iam open the task manager and select any icon by pressing cntrl button the automatic selecting problem and the slow problem will cure... What is the actual problem of my computer..? No threats founds on antivirus searching.. What i want to do..?

To me this looks more hardware problem.
What is your BIOS type ?
Ie. when you boot what is written on screen ? "Award BIOS" , PHOENIX or what ?