ReactOS is in alpha stage and not recommended for everyday use (1):
From the many " LIKES" for ReactOS one cannot conclude, that ReactOS would be also only approximately already a practically useful operating system at present.
I attribute the large popularity to the fact, that naturally all wish themselves that sometime there will be an "Open Source" Operating System which is fully compatible with the "Windows" operating systems.
In version 0.3.11 many applications do not work (correctly) because many API calls simply haven't been implemented yet. This may be one of the reasons for the software not working.

I tried to run it the VMware Player image from (2) on Vista 64 bit. But it was not possible to finish the installation of the VMware Tools from the virtual "CD-Disk" D of the guest system. I was not successful to get a stable running. But maybe the image for Virtual Box from (2) does run better.
I also like the idea of ReactOS very much, and will follow the future steps to improve it. Current and plans for future development see (3)
(1) http://www.reactos.org/en/about_userfaq.html#whynontfs
(2) http://www.reactos.org/en/download.html
(3) http://en.wikipedia.org/wiki/Reactos