for some reason my pc seems to have got a mind of its own it all started when i put another mouse in the via usb when the other mouse packed up

How do you mean, mind of its own? What's it doing that it shouldn't do, or not doing that it should?

is it an optical (LED) mouse or ball mouse?

Sometimes optical mice can creep - the cursor will sometimes inch its way across the screen without you even touching the mouse?

sometimes when ive tried to post its tried to do it twice & i get a warning must wait 25 seconds between post,s etc also if i have clicked on my internet connections sometimes 2-4 opening pages pop up??

sounds like the mouse button is giving you multiple clicks instead of just one.