OpenVMS is now owned by hp (see "h71000.www7.hp.com/" or "www.hp.com/go/vms") and is actively supported on Alpha and Integrity. This site will have links to the OpenVMS documentation. You'll be most interested in the "DCL Dictionary". You can also learn a lot just by entering "help" at the OpenVMS $ prompt.
OpenVMS cannot run *directly* on a PC. There are some emulators available to make a PC act like a VAX or Alpha. Search for "simh" and for "CHARON-VAX". If you use it only as a hobby, you can obtain the licenses you need free; there is a link to hobby information on the hp site above. If you want to use it for business, you need to talk to an hp representative.
You can buy old, small Alpha's on Ebay and elsewhere, probably for less than a PC. Same comments as far as licenses go.
You can also still buy a new, large Alpha from hp, but they will be discontinued very soon now. You can probably get hardware support for your AlphaServer if you're willing to pay for it.
By the way, the "generic system failure" message and the beeps are not OpenVMS messages. They must be AlphaServer 800 messages. If you want to troubleshoot this problem, you'll need hardware documentation on the AlphaServer.