How can I run Windows apps on a Linux Acer Aspire One?

It just read your review of the Acer Aspire One. I've had one for a week or so and find that I can't load up windows files (*.EXE), which is a bit of a blow as I wanted to be able to do basic Autocad drawings. Is there an easy way to get it to run windows files?

And what are the basic hacks needed to be able to install Thunderbird please?