I'm not sure... But do you know, your PC should have:

System Requirements
Operating System: Windows® XP (Home Edition/Professional, Media Center Edition, Media Center Edition 2004, Media Center Edition 2005)
Processor: 800MHz Celeron® class processor or better
RAM: 128MB Minimum
Hard Drive: 20MB9 Minimum availible Hard Drive space
Optical Drive: Optical Drive capable of reading CD-ROM
USB Port: USB 1.1 or faster port
Internet Connection: Broadband suggested

According to:
http://www.sonystyle.com/is-bin/%20INTERSHOP.enfinity/eCS/Store/en/-/USD/SY_DisplayProductInformation-Print?ProductSKU=PRS500

And I have found no word now about Sony Reader's processor and memory... It was there before (as far as I remember, 200MHz, 64Mb)

My PC is ready, though as I am shifting towards Linux these days, I wish Sony would remove the OS requirement.

For the hardware that would be fine but it's hard building good software without knowing the OS

I have a hunch that the software will be like ITunes. You'll build a library and it will help convert what you have if you have the propriety software ex: Word for Rtf.