I have just downloaded the latest RST version 14 I think it said because I am just about to test Windows 10 on a spare drive and have been looking for drivers for it, I have RST 12.9 installed on my Windows 7 installation but the latest version after that won't install as I get the same message as you "Platform not supported" I am using the Z68 chipset with i7 2600k CPU I'll be seriously annoyed if even that chipset is not supported for Windows 10 because I have no plans in upgrading for another few months till the next line of Intel CPU's arrive at least.
As a matter of fact we recently released Intel® Rapid Storage Technology version 220.127.116.119 to work with Windows 10 32-bit and 64-bit on motherboards based on Intel Chipsets with RAID capabilities (so far the only version for Windows 10). You can download it using the following link:
Uninstall first the previous version before installing this one.
So far we have not seen mayor problems installing or using this new version of the Intel® Rapid Storage Technology in Windows 10 and some issues we found have been corrected as stated in the release notes.
It is really hard to tell what the problem is in your case and the only recommendation we have if this version doesn't work for you is to wait until we release a newer version to see if that works better.