source make check regression test on windows xp

I’m building from source on Windows XP.  In the manual for 9.0, chapter 15.5 has a section about using make check for regression testing.

make check bombs out when it tries to start the postmaster.

The manual mentions “This won’t work as root; do it as an unprivileged user.”  -- could this be why the postmaster won’t start?  Frankly I don’t really know what this caveat is instructing me to do or avoid.  Much obliged for any suggestions.

Thanks,

John