Experiment with this .BAT script; this works in my case (Xeon, Win7x64Pro, FirefoxX64 rev54.0). Not using and deleted Internet Explorer. I was surprised to find out that over a period of ~1year the DOMStore folder accumulated in excess of 15000 (fifteen thousand! ) empty folders. (And running CCleaner 5.26 does add 4 empty folders each time. Possible bloatware/malware? TBD) I did write the below DOS.BAT script that clears and deletes the DOMStore folder and (most of) its contents: cd C:\Users\yourname\AppData\Local\Microsoft attrib "Internet Explorer" -h -r -s cd "Internet Explorer"