ReactOS does not work on any hardware that I tried, but it worked before.
Pentium 133MHz + unknown Intel motherboard
Pentium 200MHz + MS-5164 motherboard
AMD K6-II+ 3DNow! 500 MHz + M5SAA motherboard
Pentium III 550 MHz + P2B-F motherboard
Pentium IV 3.0 GHz + DG33BU motherboard
Last working version is r45270.
r45271 and later are all broken.
DESCRIPTION ON DEFECT:
PC start to bootstrap with debug bootcd inserted in drive.
After the message to press a key for starting setup, I press the key and it starts to load some files.
After loading last file (it seems "ext2.sys" to me), the screen goes blank and it stays blank forever.
Even pressing CTRL-ALT-DELETE does not reboot or wake up the machines.