My experience of winblows 10 is very limited and almost forgotten, i hated it, breaks way to often, constant borked updates yadda yadda so current w10 users will be better off advising you.
Probably my only pet hate with w7 was that Aero would crash and resort to that bloody awful fisher price basic blue theme whether i used my Godavari apu's igpu or a gt710. You had to use a 3rd party theme(and patch 7 accordingly) to get a decent theme. I actually like the Metro theme in 8+ now.
I still use software from pre and post Windows XP SP3 and they ran on w10 1607 fine. Your programs may be more picky than mine so you may have to install them with w7 compatibility. Perhaps if you list your software and include any screen grabs to show a particular problem it may help.
Sorry i cant be of more help
. Saying that if you are willing to use a graphics card then you could try 8.1, its a good os and i got my gt710 for £30 and its good enough for my non gaming and non hd video streaming needs.
Be careful though because RR has limited pci lanes compared to the cpu's.
If you are willing and able to then Ryzen 3 and 5 1000 series cpus are at decent prices but the current Ryzen 5 2600 6c/12t has a good reputation and uk price of £155, will work on your B450 board, if you dont want to overclock it then grab a Ballistix ddr4 3000 kit as Ryzen is currently using showing max stock ram speed of 2933. You can use 3200 though.
