Even after installing latest build, deleted assets still missing, how do I get them back?

Hello, I accidentally deleted some texture assets and have no way of getting them back. I even uninstalled and then installed the latest version of Unity, and they're still not present. I frequently do disk cleanups so they're not in the recycle bin either. This is really impeding my progress in learning and unless this can be resolved I'll have to learn Unreal instead I think. Can anyone assist please?