I rec'd the computer Jan 08- It would have been version 3. ?

something- I purchased the 4.0 upgrade and have done the upgrades as they happen- I have installed another djing software rock-it-pro that I have not even been using. There is a recovery software on the computer. I have a walmart music download program- and whatever programs that MTU put on the computer-I am wondering if I should reinstall 4.8 just in case all of the windows updates were not complete before I installed it- I also have a Norton 360 anti-virus program-I have since doubled checked updates- did the custom updates- changed the suggested settings