Advice on buying a good used laptop?

The first three used laptops from Ebay were generally solid. The next three all had various issues though one came in a known not working state and turned out fine after intalling a hard drive, video card, and memory.
I have decided that buying units with swapped out operating systems may be dicey. I think people try replacing operating systems to "fix" bugs....which may not work. Units that are virtually unused may also come with significant issues. Which brings up this possibility: Would people normally sell a perfectly good laptop? Well.........sometimes they just want the latest and greatest?
Turn out that orking on the fan got it to ork a little bit no. Too bad that a couple letter do not work now. Not too bad for a novice.
I have decided that buying units with swapped out operating systems may be dicey. I think people try replacing operating systems to "fix" bugs....which may not work. Units that are virtually unused may also come with significant issues. Which brings up this possibility: Would people normally sell a perfectly good laptop? Well.........sometimes they just want the latest and greatest?
Turn out that orking on the fan got it to ork a little bit no. Too bad that a couple letter do not work now. Not too bad for a novice.
First Bank:16 180 watt Grape Solar with FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Anyway I bought a newish laptop that was "used a couple times" before having the manufacturer change the defective hard drive. The newer laptops are often lightweight and very energy efficient. Dang.....some gaming laptops go for a few thousand dollars. Paid $250 for mine... The $150 laptops seem to have issues...
Why..operating system becomes obsolete (thank you Microsoft).
Windows 10 made my older laptops useless, not enough memory to upgrade, older laptop is limited to small memory upgrades. then you get the XP and VISTA warning where you can no longer use IExplore or Google Chrome.
You will be better off buying new for these reasons.
It also looks like Microsoft office is now a subscription, forcing us to buy it every year.
My older Microsoft office will not load on new machines, somehow the product key get blocked by Microsoft.
19 SW285 panels
SE5000 inverter
grid tied
The greater reason for going 10 is the lightweight and energy efficiency of the newest laptops. Solar aficianados will generally put a premium on energy efficiency.
I consider Microsoft to be a somewhat evil entity but great options are not readily available.
All free and stable. Pretty compatible with MS Office (newest file types not always "convertible" between Open/Libre and MS office--I just save in an older file version to be sure).
-Bill
I'm also running Raspbian linux on a raspberry pi. It runs off a micro-sd card in a board about the size of a credit card. Even with ethernet, wifi, hdmi, and 4 usb ports, it's about the size of a pack of cards and costs <$50. Draws ~100 milliamp at 5v (plus whatever for monitor), and does pretty much everything the laptop can. I haven't tried youtube videos on it, but I suspect they'd run ok. Video intensive games maybe not so much.
My first computer had 640K ram and a 10MB hard drive. Oddly enough, I still had it 15yrs later, and needed it to handle a job in which source data had been stored on 5.25" floppies, and nothing else could read them. With stuff in the cloud now, maybe it won't be an issue, but I still wonder if we'll be trying to find a way to access stuff stored today in 15 years from now.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
My newly ordered computer has a slow 5400 RPM hard drive with 1 TB of memory! Curious. Since I saved a $100 buying used, I will probably switch to an SSD hard drive for general operations and store some truly beautific battery pics on the 1 TB hard drive.
SSD drives are reliable, but usually do not give any warning before they die.
Bill
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Billions of these small obelisks will be found dumped in a site in what was once called China.
Knowledge of history thereafter is indeterminate.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Peacefulness
Observations in the wild indicate that the males among the related common chimpanzee communities are hostile to males from outside the community. Parties of males 'patrol' for the neighboring males that might be traveling alone, and attack those single males, often killing them.[64] This does not appear to be the behavior of bonobo males or females, which seem to prefer sexual contact over violent confrontation with outsiders.[4]
Could they also get (limited, read only) access to source code? Maybe, but doubtful. Could they buy the ability to introduce monitoring code into general commercial MS software? No way. 800mm is loose change compared to the profit stream, and such an arrangement would be impossible to keep secret.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter