Cleaner registry cleaner , caused major os issues

I run win7 sp1 x64 , and have the latest build of c cleaner installed, i ran the reg cleaner part of it, backed up the changes in the programme which i always do , after rebooting the pc, windows had no sounds, the GPU was not functioning properly ie cooling fans spinning up when under load, and i was unable to access menyparts of the windows GUI menus such as control panel, my computer (so no gui access to my HDD therefore unable to find and merge the entries removed by c cleaner back into the registry, i was lucky that i had an earlier system restore point that i was able to access via F8 menu repair your computer , Why doesn't c cleaner offer the option of creating a system restore point before cleaning reg files?????

As a result, i can no longer trust this app to clean the registry glad i did not buy the pro version

G’day Tomm and welcome to the forums.

Was there a reason for running the reg cleaner to begin with?

Hi, sorry for the delay replying, I had uninstalled a security programme ESET, due to a version update that was borked, so just wanted to see if there were any remnants left after running the uninstaller tool, i have used this reg cleaner in the past always make a backup option in CCleaner before i delete the entries without issues in the past