Tried to use memtest86+ and it tries to boot but then I get following message:

I burned a bootable cd of memtest86+ and when I try to boot it gets to Dr caldara then I get the message: EMM386 Warning: Address line A20 already enabled.
And it just hangs there. Nothing else happens. Anyone know why??

 

What program did you use to burn the CD? Was it Nero by any chance? If it was then you'll need to find another program to burn the CD.

 

I did use nero for burning the iso bootable memtest. But why should that matter?

 

It's something to do with the way Nero creates iso images. Not sure of the exact details but try another program to create your iso and see if you get somewhere. Can't recommend any off the top of my head and I'm in a bit of a rush at the moment - just post back if you can't find anything and I'll sort something out.