I regularly clear my Windows temp folder by simply using Edit - Select All, then deleting the lot
It clears all files except the index file, which is protected, and it has never caused any problem. So, as far as I know, deletion of your problem should be perfectly safe.
As I understand the situation, Windows generates temp files, when installing software, to aid installation, and some, but not all, are deleted when installation is complete. Also, temp files are generated when you browse the internet and download pages. So no file in that folder should be essential to the continued functioning of your PC.
If anyone out there knows something I don't, please intervene.