how do i share my program files and windows folder so other people on my network can access them??

Run the Network Setup Wizard, reboot, then right click on the desired folder > Properties > Sharing and Security > Share this folder > Click OK.

The root of the drive cannot be shared in this way.

ah i don't think i made it clear enough i meant c:\WINDOWS system folder and c:\PROGRAM FILES system folder

Well, you can share them in the same way as mentioned above, but if you're speaking of actually running the OS or programs accross the network, I don't think you're going to achieve what you're trying to do.

Some applications (i.e. Microsoft Office), provide ways to set up administrative installations that network users can run from the network, but that's about it.

Right click on Program Files and Windows, Properties, Security tab > Share this folder, OK.