My wife and I have a nasty situation, in that upgrades and changes to formats and?

security codes cause us big, big hassles. U c, my wife is severely vision impaired n needs 2 use zoomtext (software) with very large font and high contrast screens, in order 2 be able 2 do her computer work; emails, facebook n all the really important stuff. The problem is that just as she manages 2 get on top of 1 system, format etc, Yahoo 7 seems 2 want 2 change things. It is not too bad if I'm around, but I might b working outside and I often have 2 come in 2 "rescue" her. We are both in our late 60's early 70's so these changes do not come easily 4 us. How cn we avoid the upgrades n other changes. I know we r 'dinos' but we really do love (2 hate) our puters. Ur help wd b much appreciated. Tnx inadvance.