Hi :
I assume you mean slower than normal with bloatware Norton on your computer !?
One of the possible Causes could be malware and I noticed you do NOT have
any antiSPYWARE/antiTROJAN program(s) on your computer ; would be wise to
run a "Full Scan" of the FREE Ver of "SUPERAntiSpyware" from
www.superantispyware.com AND the "Free" Ver of "Malwarebytes' Anti-Malware"
from
www.malwarebytes.org/mbam.php .
And I hope you realize "ThreatFire" is a "classical" "HIPS" program !? There are
better programs of this "type" available .
Noticed you have the malware-prone Adobe Reader ; recently, Researchers found a new hackertoolkit that uses nothing but Adobe securityleaks in order to infect systems. "PDF Xploit Pack" (
http://www.trustedsource.org/blog/153/Rise-Of-The-PDF-Exploits )adds all kind of exploits to PDF-files. When a certain exploit has successfully infected the OS, the IP address is sent to the attackers, so they need to try again. This to reduce the time it takes to manage the bots.
Use of PDF-files is becoming more and more popular among malcreants, this because other toolkits also have PDF exploits now. A year ago only 3% of the exploits were PDF directed.
So I recommend you uninstall Adobe and get the safer "Foxit Reader" .