To Take Back
transitive verb, godan verb
To take and return something to yourself is to take back something. Give it back!
The readings come from 取る and 戻す. Combine them to get this.
コンピュータを出荷時の設定に初期化することでこの問題は解決しますが、バックアップがなければ失われたデータを取り戻すことはできません。
You can solve this type of problem by restoring the computer to factory settings, but you can’t regain the lost data if you don’t have a back-up.
An update is needed before you can continue but you have more than one WaniKani tab open.
Finish up what ever you are doing on the other tab(s), then close them to continue.
The update will complete automatically once the other tab(s) are closed.