I am boggled 
Currently have a Toshiba Satellite (problems with overheating and noise, but otherwise a nice laptop).
We use programs such as AutoCAD, MS Office, databases and I like to be able to use Windows Movie Maker.
Require large screen (17"-ish)
Need plenty memory (currently have 300 or something...need about double)
At least 4gb ram or whatever that is...
Need to be able to read and burn DVD's but not fussed about watching bluray or anything.
Budget around £500
And I would prefer if it looked nice 