The first backup after an update will be quite slow (but shouldn't be anywhere near that slow). And the searching on the backup disk will have to be repeated on every backup attempt until one completes normally.
Connect to the TC via an Ethernet cable.
Also see the green box in #D2 of Time Machine - Troubleshooting. Something there may help get back on track.
(and your English is fine -- better than many who speak it natively, I'm sorry to say.)
Thank you very much Pondini !!!
Your advice was very good !! I think I will move my TC to another better and faster wireless connection. With your advice and specially the complete web page you have sent, I think the problem is in my too slow wireless connection. After this weekend I will tell you how the backup works in my home Wi Fi faster connection.
Thanks again for your help and best regards,
Thank you Pondini !!
Finally did it in my home wireless connection !! And only in few hours !!, although when I connect my MacBook Air via ethernet to the TC (ethernet port) there is no internet signal (dont know the reason), so I did it without the ethernet connection.
Really dont know what was happening with my office wireless connection (it would be faster than my home connection).
I appreciate to much your help and concern.