I don't know what you meant by "I unloaded some plugins" but if you were directed to a site that said you had many registry errors and needed to download and pay for a program named Uniblue Powersuite, it sounds like a scam to me.

If Firefox is always running, even after you restart the computer, you may have malicious software ("malware") installed. See http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Reinstall_after_completely_removing_Firefox for how to do a clean reinstall and other solutions, including how to check for malware.

Thank you Alice. Sorry "unloaded" should have read "downloaded". I was flicking through the Firefox recommended plug-ins and I downloaded one plug-in which directed me to this dodgy site. (Probably trying to punish me for not paying for his plug-in). Unfortunately I didn't keep a record of which plug-ins I was downloading and I can't open Firefox to try to check my history. I agree that it was probably malware and other people on other forums (fora?) have reported similar problems with "Uniblue". John

You should never respond to such unrequested alerts and pop-ups. Only trust an alert from legitimate (AV and firewall) software that you have installed yourself on your computer.

Do a malware check with a few malware scan programs.
You need to use all programs because each detects different malware.
Make sure that you update each program to get the latest version of the database before doing a scan.

• http://www.malwarebytes.org/mbam.php - Malwarebytes' Anti-Malware
• http://www.superantispyware.com/ - SuperAntispyware
• http://www.safer-networking.org/en/index.html - Spybot Search & Destroy
• http://www.lavasoft.com/products/ad_aware_free.php - Ad-Aware Free
• http://www.microsoft.com/windows/products/winfamily/defender/default.mspx - Windows Defender: Home Page

See also "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked and What to do when searches take you to the wrong search website