Netscape v6 works fine on my system... I'm running Win2K, 128MB RAM, Matrox G400. I don't know what other specs you want...
But anyways... be warned about Netscape... it's a memory hog. I was browsing with it here and there and found out it was using a lot (40+ MB) of memory. For the most part, it takes up about 25MB of memory... which, is still a LOT.
Other than the memory issue, Netscape 6 is a much improved browser of the 4.x versions. I think I will stick with IE though.