I'm chiming in late on this, so most of my thunder has already been stolen. Aside from the video editing you mentioned, I don't think you really need much in the way of hardware for the tasks you mentioned. More memory is always better, storage/processor appropriate to the task.
All that said, it does sound like an OS issue. I generally keep my data in a couple different places (server, external hard drive) and the really critical data (vital docs and family photos) also on several encrypted USB thumb drives. With a setup like that, I don't feel so bad when I need to nuke from orbit and start over.
Fortunately if you do go the route of purchasing, you get a lot of bang for your buck these days. I just got a $200 netbook that beats the pants off the desktop I bought 13 years ago for $1600. grin

Oh, and I am also happy to help with questions and/or monetary donations toward new equipment. I appreciate what you and ETS do for the preparedness community.