My pro is 500 GB HD, 4 G Ram. I have used less than 90 GB total. I tried to update the OS from Mavericks to High Sierra and it "crashed and burned" even though HS specs on Apple said it would work with my computer. Here's the dumb part: Never backed up anything! Took it to repair shop. Told that my hard drive is damaged and need a new one. Here's a copy of the diag. report: 1. Began eval - Pulled 500GB 2.5" Hitachi SATA HDD from machine - S/N: Q7KZ6H8V - Apple S/N: IX0250WNJDWPA 2. DR eval on DDI N - Disabled SMART successfully. - Building heads map (0-3) . . . OK - Media test showing possible damage mid H3 3. Began imaging - Steady @ 71MB/s 1. Imaging complete - 154 UNC, mid-scattered Here's a breakdown of the repair costs with new HD options: (I need a new battery, also) Data Recovery Diagnostic 1.00 $75.00 $75.00 MMS-DR Data Recovery 1.50 $200.00 = $300.00 MMS-HW-LBR1 Tier 1 Service Charge 1.00 $75.00 = $75.00 MZ-76E250E Samsung 860 EVO 250GB 2.5 Internal SSD 1.00 $119.00 $119.00 [WD5000LPLX] Western Digital Black 500GB 2.5 Internal Hard Drive 7200RPM SATA/600 $79.99 BAP15MBU78N NewerTech NuPower 78 Watt-Hour Battery for MacBook Pro 15" Unibody $99.00 Mid-2009 & Mid-2010 1.00 $99.00 Including crazy city tax, it all comes to a whopping $727, and I really don't understand the diagnostic results. So I'm wondering, will upgrading to a SSD make my laptop run better, and should I just have Mavericks re-installed, as High Sierra seems to make it lag, based on what I've read. I don't want to upgrade to 8 Ram. And then I have to buy an external HD to back up whatever is recovered, which is another $60. And isn't $300 a lot for retrieving documents and pics. Oh, and I have to get MS Office. Another place I called said they still have brand new apple batteries for my Mac. Is it better to get one of those or do they deteriorate somehow if they have never been used? Which OS will work best on this with a new SSD? Any reccs for good, less $$ tech shop in NYC? Thanks so much for your time and help!