PC's nowadays usually come pre-installed with the operating system and no backup disk.
I've got Windows 10 on my PC and laptop and had no problems except for it insisting on doing updates just when you don't want them and stopping you from using it!
Yes, you have to be wary of staff at PC World - when I bought my current PC they tried to tell me my Microsoft Office 2010 wouldn't install and tried to sell me a later version.
Pack of lies as it installed as sweet as a nut.
Well you were not wrong
Been a fraught few days but we seem to be up and running with a new HP desktop...yep it's got Win 10 pre-installed
Minor problem with our net connection, it didn't work !
Hope I've sussed and fixed it now, diognostics? if you have a problem call me..
No don't really mean that !!! ,I'm a spent force now ...going for a lie down
JaB.