I have what I think is SP1 running and it seems to be very stable. I downloaded a file from this forum named Windows6.0-KB936330-X86.exe which weighs in at 455,562,200 bytes on my disk.

The MD5 hash is D597866E93BC8F80ECCA234C4E9CE5A2 which matches what the download link said it was and also matched a hash given by Adrian Kingsley-Hughes for the X86 version of SP1 on ZDNet.

After install Winver.exe reports: Version 6.0 (Build 6001: Service Pack 1)

Did I get the real deal?