No you don't, Windows XP SP2, SP3 or Vista as is with all new Microsoft software such as Windows Media Player and indeed most new software now. IE7 was released before Windows XP SP3 as was IE8 Beta.

As for the slowing the PC have never come across this before I did hear that XP SP3 was a bit unstable after it's release but think that was just talk and have never experienced any problems with it.

Are you sure it's defently SP3 and not something that was on PC as you now have clean install you could try and again and always uninstall from Add/Remove if you get problems again.

If you ever had Windows XP pre SP2 release you would have noticed alot of difference visually but also new features such as the Security Center and big security changes such as Windows XP Firewall being enabled by default just to name a couple of minor ones.

With XP SP3 visually you will not notice no difference, there are two major background changes that do not really affect end user.

1) Support for IPV6 (Internet Protocol version 6)
2) Support for WPA2 (WI-FI Protected Access 2) Basically new wireless encryption technology.

There is also another feature added called NAP (Network Access Protection)

It's basically just added features that Windows Vista has.

It is good practise to run the latest service pack and if not will just sit in the system tray with the yellow shield waiting to be installed and this can hamper the performance of the PC as Windows Update hammers system resources. You can of course select to not be notifed of the download by clicking the shield and checking the box and just manually download later if you want.

Kind regards,

Martin.