At the risk of being a pessimist here, unless the machine was prepared for long term storage, purging the lines and filling them with material that does not cure, the hard drive/computer issue is going to be the least of your worries.
Before you spend too much time on the computer, check to see if there are material cartridges installed, and if so, what type. If someone left the machine powered down, filled with resin, you’re looking at replacing all the lines, the pumps, and the print heads. The replacement cost on each head is about $1500US, plus labor.
