Help needed, deleted temp folder content.

Hi all,

I watched a YouTube video regarding how to speed up windows 8.1 and the instructions were to delete the contents in the temp folder, %temp% folder and prefetch folder. Some of the contents could not be deleted and after deleting some of the files, some of my programs are not working - I can't install google chrome, can't update adobe and Hp support assistant stop working. I did a system restore but it says it did not restore completely due to an error. I tried to restore all of the deleted files but they said it failed and asked me to try again which I did and still could not. I tried changing permission in the temp folder properties but it failed too. Would appreciate any help :(