I don't have tested it on Windows 8 but you can do it.
Download RealCADD and install it.
In demo version, you can't save files but all other functions work normally.
Hello Eric
I have tried RealCADD on windows 8.1 on a surface pro 3 and it seans to work very well. I did not find any issues within the limitations of the demo version.
Cheers
Grahame