I used a friend's mac to make some changes to a CAD plan that i'd created using my own draftsight (windows vista version).

I saved from her mac.

Now when i try to open the file from my PC it says: 'this version of drawing file is not supported'

I've spend several days on these drawings so I really need to find a way of quickly converting them so I can open them and work on them from my PC.

Can anyone help?

Do I need to save them from the MAC in a different file type?

Many thanks in advance!

Tabitha