System Requirements

Microsoft Windows 2000, XP or 2003
We also recommend installing the latest service packs for maximum performance and security.
64MB of RAM
If you have less than this you are usually lucky if Windows even boots properly. OmniSecure itself takes up about 2MB of memory when active. More memory allows the operating system to cache file accesses, which improves performance.
At least 2MB of hard drive space.
You obviously need more if you are going to serve content. A small web site may only need up to 3MB to 4MB of space. (OmniHTTPd will run on a floppy but you then become seriously limited as to the quantity of documents you can serve. People actually do this so don't laugh.)
A functioning TCP/IP stack.
Note that while direct Internet access is not required, an active TCP/IP stack is required for local testing.