I found Min sys requirements on the Wiki
"Whether installing
ReactOS on real hardware or on an emulator, it is important to know the minimum requirements to install and use ReactOS:
- 32MB RAM (NOTE: Debug builds may require 72MB of RAM, please use a release build on low memory systems)
- IDE harddisk (not SATA)
- FAT16/FAT32 primary boot partition (NOTE: boot partition must be the first partition on the disk)
- VGA compatible video card (VESA BIOS version v2.0 and higher)
- Standard (PS/2) keyboard
- PS/2 compatible mouse or Microsoft Mouse compatible serial mouse
Furthermore, if you want to try
TCP/IP networking, one of the following
ethernet cards may work:
- NE2000 clones (Such as Realtek 8139)
- AMD PCnet32 LANCE
Other cards might also work, if you provide the appropriate driver."
Unfortunetly no mention of minimum processor speed