In your system there is no virus but its running very slowly.
in this case you need to check your ram capacity or do u want decrease
pressure on RAM you need to follow these steps
My Computer ==> Right click my computer and go for "advanced TAB" and follow below screen and choose Adjust for best performance
click K and restart you will find some difference in pc speed and it's applicable for Windows7 also to the same process
My Computer ==> Right click my computer and go for "advanced TAB" and follow below screen and choose Adjust for best performance
click K and restart you will find some difference in pc speed and it's applicable for Windows7 also to the same process