>1. Left "server" PC only as server
>The "server" only used as data storage. Data entry and report generation will be done on other workstation
>

It is OK, so only try to solve switching disk cache off problem (maybe you should change disk)

>3. It seems that at this number of concurent user and sales transaction you should use true server rather then peer to peer environment
>What do you meant by real server? Do you meant the machine or database server?

I mean Win2000 server edition. At this number of users VFP should work quite good on it.