Update of new version (2.1.35) not possible

I haven´t used Anki in a while. Now I want to use it again, but the App is starting a check of the media data. It doesn´t stop and I´m not able to open the App or to start the Update. I have not downloaded everything before. But I need all my cards. Online I can open all my cards. I´m not sure what to do and if I will lose a part of my data if I will deinstall the old version and install the new version. I think the problem is that the old version isn´t compartible with my version of windows anymore.
Any advice?

Please see https://faqs.ankiweb.net/when-problems-occur.html