This file you mention should be an executable. It will install it where it needs to go. If you want to read up on this more I will include the link directly to microsoft about this download. Download details: Platform SDK Redistributable: GDI+
And you also pointed out what I was going to say, it should work as your operating system is listed as one of the supported systems for this installation. The best you can do is try it and see if it works. If not then you may want to just install xp and get it over.