HELP!!!! Update broke unity

Ok so Ive been using 5.3.5 for a long time yes i know but for some reason i decided to update but shut it down half way through know how it would effect my current project now if i try to launch unity this screen pops up that says Copying C:/Program
and a whole bunch of other crap i half to hit cancel on it takes me to the project menu but if i try to open a project or start a new one either unity stops working the second it opens or it never opens at all

Please anyone who can help me i have an entire game nearly finished in this

First of all, don’t press cancel ever if you don’t want to risk data corruption. Second of all, before attempting to update Unity, backup your project. Lastly, 5.3.5 will likely have nothing broken with the new Unity. If your Unity is not opening, do a full reinstall.