Hi,
wraith, and welcoem to the forums.
By default, the only security product that comes with Vista is
Windows Defender. Bit Defender is a *completely different* antimalware product. If you didn't install it, someone else did.
However, before we go this far, you need to realize that saying things like

Originally Posted by
wraith a box comes up and say something like,programme stop due to something
does not help us. We need exact details on what is being said. Same for the message you receive afterward when you send the error report. There should be a link you can click to see the report online, if you provide that it would help as well.
However, going back to the problem - as long as it is *BitDefender* and not Windows Defender, you can disable BitDefender by running the program and disabling it.