We have not tested RegVac in Windows 8 yet. I do not know when we will. A user ran A1Click and RegVac in Windows 8. This is what he said, "A1 seemed perfectly fine. Regvac ran OK (I used admin privileges on both) but didn't delete everything it found (skipped at least a third). Afterwards my folder associations disappeared and I was unable to open folders until I found a registry fix on the internet and restored the function.(http://www.winhelponline.com/blog/file-asso-fixes-for-windows-7/)" That is all we have heard about RegVac's compatibility with Windows 8. We did not hear back from this user as to whether RegVac worked after the above fix or not.