2011 27" iMac very sluggish.

[nStyle]

Long story short:

Just had a power outage.
Mac cut off.
Turned Mac back on.
Started Firefox.
EXTREMELY sluggish performance.
Safari is much better but something still doesn't feel right.
Tried reinstalling Firefox, no luck. Firefox freezes and won't close unless it is forced.

Any ideas guys? Why would Firefox all of a sudden turn rotten just because of a little power outage?

Mind you, I have no surge protection or anything at the moment but I have just ordered an APC 1000w UPS backup unit.

 

[Michaelgtrusa]

Make certain that you have deleted all the firefox files on you're mac and download agin.

 

[Voondebah]

I would suggest trying to Repair Permissions.

 

[Drag'nGT]

Try Appcleaner http://www.macupdate.com/app/mac/25276/appcleaner
Then repair permissions.

After that find a cheap battery back up. They're usually $30-50 and give you around 45min of use after a power failure. Plenty of time to turn off the computer and other electronics. Worth every penny.

 

[MythicFrost]

Make sure the disk is OK: Disk Utility > Verify Disk

 

[coolspot18]

After that find a cheap battery back up. They're usually $30-50 and give you around 45min of use after a power failure. Plenty of time to turn off the computer and other electronics. Worth every penny.

A cheap UPS is usually only 300 - 350VA, and that won't last very long, perhaps 5 minutes for 27" iMac (~310W). For a decent runtime, the OP will need a UPS with >1000VA capacity.