If it's any use to you I bought a second hand Lenovo T420 laptop for around £150 and can't fault it. It came with Windows 7 that can be upgraded to Windows 10 although I recommend sticking with 7.
You can create a bootable diagnostics USB stick to test the individual components. https://pcsupport.lenovo.com/gb/en/leno ... tablediags
I use this utility on a day to day basis as I work for a major IT company who are a partner with Lenovo, I also hold the Lenovo accreditations.
Richard
Opinions are like people,everyone can be different.
We had 7 reinstalled on our laptop, as it's more reliable. The computer man says sorting Windows 10 problems occupies much of his time. Seems the "Village idiots" at Microsoft haven't got it right. On my work computer, I still have XP and it does all I require of it.
Personally I'd avoid Lenovo, not had the best experience with them as an IT tech. Used Dells or HP have better support. Dell have excellent built in diagnostics. If HP, download their UEFI diagnostics to an empty USB drive and run the full test.
There are several places selling fully tested ex-corporate machines. Usually these are well spec'd and have had the Hard Disk replaced.
I would advise against anything Packard Bell, Acer, Medion, eMachines.
All of the main line brands are fiine, I do agree with steering clear of the lilke of packard bell, medion, acer etc - limited or no support.
As mentioned the places that sell on ex corporate machines are worth a look, as corporate machines tend to be shosen for being reliable. I have had several Del laptops now, all given to me by employers and they have been decent relaibel no frill machines. Infact I still have one that over an upgrade was told if you want it keep it, now my personal laptop and is probably 4 or 5 years old.
I bought a Dell Small form desktop like that and its a cracking little box.
W10 is fine, 8 should have been buried quickly, much like Vista.
My HP Pavilion 6th gen i7 with 8gb RAM and a 2GB Hard disk was only just over £500 and runs like a demon once all the Win 10 snoopware was disabled. As a minimum spec you want an i5 processor, 4GB RAM, a 1TB HDD and a 1080p screen. Don't go for touchscreen, unless you like fingermarks all over the screen! If you are buying used such a spec should be under £300.