Inactive Computer sluggish, pages deconstructing

Thank you Broni, I will do both right away.
Thanks for all your time and help. I just don't know what people like me would do without WindowsBBS and people like you.
You are very much appreciated.

 

Slight Problem...as I was uninstalling Mozilla I now have a pop up box from ThreatFire.

ThreatFire has detected a potential threat.

Very High xxxxxxxxxxxxx

File name:
C:\USERS\JULIANNE\APPDATA\LOCAL\TEMP\~NSU.TMP\AU_.EXE

Suspicious Action:
This program is attempting to modify the way your computer communicates with the internet.

Threat type:
This attack typically appears in adware

I have not done anything because I don't know what to check in the boxes.

1. Allow this process to continue
2. Kill and quarantine this process
3. Kill this process

4 Remember this answer

I don't know if it is just the uninstall or some other problem triggering this.

 

Once again, thank you.