Need help finding elusive files on my laptop hard drive.

Windows Explorer is not the ideal method to search for files taking up drive space. I'd suggest the freeware TreeSize Free, which has been very helpful to me over the years tracing down space hogs. You can right-click on any drive or folder to get a detailed breakdown of file sizes.

Combine with CCleaner, which can also be set to custom delete files not included in their default config, should go far in cleaning up unnecessary files.