I can't guess which tablet that was, but most of the time this takes us rooting the tablet or installing a clean Android OS.
Read https://forum.xda-developers.com/general/rooting-roms/root-intel-z2520-4-4-2-jun-3-2014-tmax-t2968974 to get an idea what work is involved.
Sorry but no, I don't offer much help in rooting. While I do this sort of work, I found we have to be willing to roll up sleeves and dive in.
I bought my husband (a non-techie) an AARP Realtab, thinking it would be easier to use. It isn't. The promo and "we want to follow you" pop-ups are annoying at best, and intrusive -- then they can't be overcome. The tablet is stuck on "Allow us to follow you..." If you try to say "No, thanks" you are stuck. No, I don't want them access to the tab. (I've since bought him a Samsung that works even better, but would like to still use the Realtab.
Is it possible to root the tablet to just Android?