>>mouse_+(OP)
Behind a NAT you're safe even with Win9x. Idk about XP-latest, but you don't want to connect a fresh pre-SP installation right to the uplink cable. I wouldn't do that with any version of windows, even from the "windows server" line.
>>wruza+td4
Curiously enough, the youtuber who tried this with windows XP did the same thing with Windows 98 [1]. And it gets hit by strange packets and scans, but that system was fine even when running for a day or two.