Yes you can delete the backup folder as Hijackthis should have been installed like a regular program, You must have downloaded the stand alone exe.
Are you sure the defender.exe file is still there? Please do one more scan for me, this may take a few hours so you can post the log tomorrow if you wish as i'll be going to bed in a hour or so anyway.
Please download and run the ESET Online Scanner
Disable any antivirus/security programs.
IMPORTANT! UN-check Remove found threats
Accept any security warnings from your browser.
Check Scan archives
Click Start
ESET will then download updates, install and then start scanning your system.
When the scan is done, push list of found threats
Click on Export to text file , and save the file to your desktop using a file name, such as ESETlog. Include the contents of this report in your next reply.
If no threats are found then it won't produce a log.
I appreciate your help. I have to go to sleep now b/c I didn't sleep well last night. Thanks again