I installed it on Win7 -64 bit, but the installed version blurs the image so bad it's impossible to really see if it works without paying the $16 for it.
Installer places it in C:\Program Files (x86)\Jim Keir\Lightroom SoftProof. User choice requires on to download the zip version and manually place the files.
Problems
(1) blurs the image drastically and (2) labels most of my profiles as "trial mode", so you can't really check it out without buying it (as someone else in the forum said it's too bad he doesn't have an unrestricted trial mode (which may even paste the words trial across the image), but at least you could compare a quality soft proof effect on screen vs the print.
John Keir also requires you to update your catalog before it will work, (and recommends you have a backup before doing that!)
- and Lightroom will not open after the install without either updating the catalog, or disabling the plugin. Fortunately, I had a backup from a few minutes earlier, but still it was not a warm feeling knowing that the catalog had to be modified, and taking it on faith that nothing would be damaged. No details on what this softproof update does or why it is required before LR can use the plugin.
I looked at it for a few minutes, closed LR, uninstalled it through Revo Uninstaller Pro, and replaced my LR catalog with my backup copy.
It looks like we are inching towards soft proofing in LR finally, but, we are not quite there yet.