looking for remote assistantce software

long story short, a friend of mine is newly online, while she does have some computer literacy she does still need quite a bit of help with setups and a little continued support.

so basically lm looking for software that would allow me to remotely manage her setup until she is confident of managing her computers herself, not to mention that her PC is located in her bedroom and she would prefer me to be able to set it up (install software and such) from her living room, not to mention that ld be able to help her out when lm at home and not physically at her residence.

either way lm looking for something simple to install and use thats secure that will allow me to access both Win8 and 10 based systems (her PC is Win8 and new laptop Win10) tho l will be using a win7 setup from either my PC or laptop (my laptop has recently been downgraded as l hated using 8.1).