This is from MC10 Help. It is not updated yet.
System Requirements
Hardware Requirements (minimum)
600 MHz Pentium
32 MB RAM
40 MB Free hard drive space
Sound card
Video card
Microsoft Internet Explorer I.E. 5.0 or above
Internet connection (recommended).
Optional extras:
TV Tuner card (for TV playback, recording etc.)
Soundcard with multiple outputs (for multi-zone playback)
CD Writer (Optional) installed and functional for creating CDs
Printer (optional) for printing jewel cases and CD labels
Software Requirements
Windows 98/NT/ME/2000/XP
MicroSoft Windows Media Player.
RealPlayer, QuickTime and Microsoft DirectX are required to play certain proprietary files through Media Center.
The 32 MB is the amount of free memory required. Total memory should be 256 MB or more. Things start running smoothly with 512 MB. I experienced that recently when I upgraded my 256 MB / 2.5 GHz P4 laptop to 512 MB.
Processor speed is up to you. Everything will work with 600 MHz, but usually over 1 GHz is needed for e.g. smooth hi-res video playback.
I would recommend Windows 2000 Professional or XP. Some 98/ME users have had problems with the beta version.