I am not sure why you could not register at the Easeus Forum. I visit them daily and the Forms are working. Here is the link to their support page:
They only provide free technical support for the paid edition, but you could email them any ways. They are very good about responding.
I have to endorse the recommendation made previously to download and install WinDirStat. It will show you what files are taking up space on your hard drive and their relative sizes. If ETBH is responsible for "owning" 38 GB, then that will show up as a very big and obvious box.
If you confirm that that the 38 GB is being "held" by ETBH, then I could post in the Easeus Forum, if you still can't get in or get no reply to your email. I could link to this thread and ask them to check it for you and get back to you. You would have to PM me with your email address (don't post it here - it could be "harvested" by spammers).
I also concur that you DON'T want to start hacking at your registry unless you have precise instructions from Easeus Tech Support. ETBH does install low-level drivers and unless you used Revo Uninstaller Pro, or a similar professional uninstaller, there might be remnants left. Windows Control Panel is notorious for leaving all kinds of junk behind, the reason I never use it. Also, if you decide to attempt a registry hack, ENSURE that you export your registry FIRST to a USB drive, and ensure that you have a CD/DVD which will boot your computer into Windows so that you would be able to restore the backup of the registry in case the hack goes awry, and that happens much too often. Dangerous place, the registry.
Hope this helps. Have a great day.
Edited by garioch7, 04 February 2015 - 03:57 PM.