You may consider buying two computers.
I bought two of the exact same computer and mirrored the drives once they were setup. I use Google Drive to sync any files that subsequently change. That way if one goes down you have access to an immediate and exact replacement while you figure out whats wrong with the first one.
ALL computers WILL fail in time. Viruses, hardware failure, hard DRIVE failure, accidental software or configuration changes can be insured against with having a backup on hand. You may have a printer problem and want to find out if it's the computer or printer and having a exact spare can help diagnose that.
Having your files backed-up is a good first step in insuring you don't loose everything you worked for, but having a complete spare PC insures you don't shut down for a few days if something goes wrong.
Back in 2004 we ran all of our cutters and printers off one XP machine. That thing died one day and I ran to Best Buy to get a new one. Spent all day loading everything to discover we couldn't get the drivers for our Roland printer to work. They were not compatible with Vista. Tried to load XP on the new Vista machine but again had driver issues. Went back to best buy and they didn't sell XP's anymore. Had to order an XP from Dell and after 4 days we were back up and running. The amount of $$ for a spare PC is nothing compared to the business we did in a day. This happened again to me and after that never went without having a spare. Computer issues are WAY too common.