Firefox is slow, freezes constantly and has "unresponsive script" errors

It'll also take ages to open Firefox. These things have all been
happening for the past month or so and it's becoming increasingly
annoying. I'll have bouts of good times where Firefox runs perfectly
but most of the time I'm having to deal with slowness and freezing.
I've recently cleared out space on my computer so I know it's not a
memory issue (as far as I can tell...I have plenty). It's certainly not
my internet because it runs smoothly, when Firefox decides not to be a
butt. Not to mention I've never had connection issues with my internet.
I've been thinking, recently, that it might be a virus or
spyware/adware or maybe even a faulty add on (though I don't know if you
guys could help with the add on one). I decided I'd run my anti virus
software, that my uncle put on my computer before giving the thing to
me, but for some reason it says it can't connect to the engine or
whatever.

So frustrated!

So I'm turning to you guys
for some help. I'd really like to get my browser running better so I
can have a better online experience.
_________________
Hello.

Download OTL by OldTimer to your Desktop.

• Close all windows and double click OTL.exe
  
• Click Run Scan and let the program run uninterrupted
  
• It will produce two logs for you, one will pop up - OTL.txt, the other will be saved on your Desktop - Extras.txt. Post both logs in this thread.
  
• You may need to use two posts to get it all.
  
• _______________
  
• OTL.txt file
  
  
• .....................
  
• _____________________
  
• Hello.
  
• Download combofix from here
  Link 1
  Link 2
  
  1. If you are using Firefox, make sure that your download settings are as follows:
  
  * Tools->Options->Main tab
  * Set to "Always ask me where to Save the files".
  
  2. During the download, rename Combofix to Combo-Fix as follows:
  
  
  
  
  
  3. It is important you rename Combofix during the download, but not after.
  4. Please do not rename Combofix to other names, but only to the one indicated.
  5. Close any open browsers.
  6. Close/disable all anti virus and anti malware programs so they do not interfere with the running of ComboFix.
  
• We need to disable your local AV (Anti-virus) before running Combofix.
  
• See HERE for how to disable your AV.
  
• Double click on ComboFix.exe.
  
• Follow the prompts. NOTE:
  
• ComboFix will check to see if the Microsoft Windows Recovery Console is installed.
  ***It's strongly recommended to have the Recovery Console installed before doing any malware removal.***
  
  **Please
  note: If the Microsoft Windows Recovery Console is already installed,
  ComboFix will automatically proceed with its scan.
  
• The Recovery Console provides a recovery/repair mode should a problem occur during a Combofix run.
  
  
  
• Allow ComboFix to download the Recovery Console.
  
• Accept the End-User License Agreement.
  
• The Recovery Console will be installed.
  
• You will then get this next prompt that asks if you want to continue the malware scan, select yes
  
  
  
• Allow combofix to run
  
• Post C:\combofix.txt back here.
  
  Note:
  Do not mouseclick combofix's window whilst it's running. That may cause it to stall.
  
• _______________________________
  
• Hello.
  
  Click Start > Run and copy/paste the following bolded text into the Run box and click OK:
  
  ComboFix /uninstall
  
  This will also reset your restore points.
  
  Run ESET Online Scan
  Please do an online scan with ESET Online Scanner. Please use Internet Explorer as it uses ActiveX.
  
• Check (tick) this box: YES, I accept the Terms of Use.
  
• Click on the Start button next to it.
  
• When prompted to run ActiveX. click Yes.
  
• You will be asked to install an ActiveX. Click Install.
  
• Once installed, the scanner will be initialized.
  
• After the scanner is initialized, click Start.
  
• Check (tick) Remove found threats box.
  
• Check (tick) Scan unwanted applications.
  
• Click on Scan.
  
• It will start scanning. Please be patient.
  
• Once the scan is done, the log will be saved here: C:\Program Files\esetonlinescanner\log.txt.
  
• _______________Hello.
  
  Go to Start > Control Panel > Add/Remove Programs and remove the following programs.
  Updating Java:
  
• Download the latest version of Java SE Runtime Environment (JRE) 6 Update 23.
  
• Click the "Download JRE" button to the right.
  
• In the Window that opens, select your platform, check the "agree" box, and click Continue.
  
• Click on the link to download Windows Offline Installation and save to your desktop.
  
• Close any programs you may have running - especially your web browser.
  
• Then from your desktop double-click on jre-6u23-windows-i586.exe that you downloaded to install the newest version.
  

Then download and install Adobe Reader X

________________
Still getting unresponsive script errors from firefox. They're not
every second or anything but they're frequent enough to really make
browsing the web unpleasant at times.

EDIT: Doesn't seem like
it's running as slow as before though, so doing those things seems to of
helped a bit. I just have no clue what could be causing the
unresponsive scripts. Ugh.

EDIT #2: I haven't had an
unresponsive script error since I first restarted firefox after
reinstalling adobe reader. Which is a huge change. We'll just have to
see what happens next time I load my computer up and load firefox up.
If it doesn't pop up with a billion unresponsive scripts before actually
loading then I'll love ya forever. Hah