BACKGROUND My 2010 MBP with 4 GB RAM, 500 GB HD (80% full), running El Capitan, is barely limping. It's got the GPU panic issue, triggered by OS upgrades beyond 10.8.6. Thanks to folks here for explaining how address that problem! I was all set to schlep to NY and get the capacitor replaced when the original hard drive started to act slow. I used my free-with-Comcast Norton Internet Security program to clean the hard drive,which I thought would help, but it was a disaster. Symantic tech support had to remotely remove the program from my computer, which stopped the spinning beach ball, but everything worked even more slowly after that. I tried to backup using SuperDuper!, but it kept failing because some files couldn't be copied over. SuperDuper! gave me a terminal command to skip the undreadable files, so I've at least been able to copy the bulk of my hard disk. At this point, if I want a chance in hell of being productive with this machine, it seems I need to replace the capacitor, get more RAM, and replace the hard drive with an SSD. And honestly, even I can see it likely makes sense to get a new machine rather than try to keep this machine on life support (but it was a good run, right?) QUESTIONS Until I decide on which new machine to get, can folks in the know provide guidance as to whether I can improve the sluggish hard disk that the SuperDuper! guy says is failing? * Should I run fsck in single-user mode? * Would Disk Warrior help? I don't know whether to just hold tight until a new machine arrives or take some steps now that might repair the disk and at least make for a smoother transfer of files to a new machine. THANKS to the community. This is my first post, and I fear I've been too wordy.