Photoshop 7 has not been tested and has compatibilty issues with Windows 8.
As mentioned on the link provided by you, there are still 10% chances of failure.
Adobe does not declare a product version to be compatible with any OS unless there is 100% compatibility.
So you can try installing it but we do not guarantee that all features will work on that platform.
The current version of Photoshop is CS6 (ver.13) which is compatible with Windows 8.
While I acknowledge that the sample size is a bit small, what is Adobes standpoint on the issue that according to these numbers the chance of failure with Photoshop CS6 on Windows 8 is much higher than with the older version?
I have already stated Adobe's standpoint in the post above. We do not check Windows forums to check our product's compatibility with the OS instead we test it in house before releasing.
I suggest try installing PS7 on Windows 8 and check for yourself if it works fine for you or not.
Photoshop 7 predates Photoshop CS 1 in 2003. I do not care what Microsoft says it will not run in Windows 8 well, especially if you have the 64-bit version of Windows 8. New computers and new operating systems frequently require new software. If you are talking about Photoshop Elements 7, that is whole different kettle of fish.