My Macbook Pro (Mid 2012) freezes or is slow to login

Question

Hi, so this issue has occured for a while, but my Macbook Pro 13-inch Mid-2012 freezes occasionally on my login screen. A couple of things happen when it does this.
Either it freezes and there is no blinking cursor in the password box and I can't move the trackpad/if I do move the trackpad it just turns into a spinning beach ball for 20 seconds and then it finally allows me to log in. When I log in, for a few minutes everything on my computer is sluggish, for example going to my launchpad takes time and opening up applications takes time.
Or, it will do all of what I just stated above but it is preceded by a sound as if it were booting up from shut down (that mechanical disk sound that always happens right when you press the power button to boot up the computer) and then following this, the screen is brightened a lot and there is a white loading bar at the bottom of the screen towards the middle. The loading bar is like 15 or so transluscent white horizontal lines that become solid white to indicate loading. This may take a few seconds and then it does exactly what I stated in the previous paragraph.
This issue has happened for a while, and I'm not sure what the problem is. Please help! It's frustrationg to have to take 30 or more seconds to wake up my computer and begin using it.
I am running OS X Mountain Lion 10.8.3 on a Macbook Pro 13-inch (Mid 2012) with 4 GB of RAM and 2.5 GHz Intel Core i5 processor.

Answer 1

When I log in, for a few minutes everything on my computer is sluggish, for example going to my launchpad takes time and opening up applications takes time.
User Tip:  Why is my computer slow?
What to do when your computer is too slow
Speeding up your Mac
It's frustrationg to have to take 30 or more seconds to wake up my computer and begin using it.
Check your System Preferences>Accounts>Login Items.  Get rid of and/or delete all that you do not need or want.
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If you found no solutions to your problem(s) listed in the various Knowledge Base Articles see if the following suggestions are of any help:
Except for the keyboard & mouse, disconnect all devices/peripherals from your computer.
Step 1:  Restart into Safe Mode by holding down the Shift key during startup.  The comp will run a complete & lengthy file system check, then start up w/only the required kernel extensions & w/o running any Startup items that you installed.
If you are running OS 10.4 it will also perform some font finagling.
Try starting up normally again.  If you are still stalling, restart in Safe Mode & move on to Step 2...........
Mac OS X: Starting up in Safe Mode
Step 2:  Open Library>Startup items folder-the *root* level Library, not the one in your user name folder.
Look for potentially problematic 3rd party items such as virus scanning software components, etc.  Remove 1 or more items to a location outside the Library folder, such as the Desktop, then restart normally & see if your Mac stalls.  It it does, try removing all the items in the Startup items folder & restart.  If all’s now well, place the items back into the Startup items folder 1 by 1, restarting each time you put one back.  If and/or when the stall resurfaces, you just identified the faulty component.
If the above does not work, then it’s time to move on to Step 3.................
Step 3:  WARNING-This step can be tedious-removing .plist files from the /Library/Preferences folder.
Remove the entire Preferences folder from the Library folder on your startup drive then place the files back 1 by 1 until you see the problem return. *The Mac will automatically create a new Preferences folder in the Library folder*
Alternatively, you can take half of the items out (all non-Apple .plist file, for example), restart to see if your Mac stalls, then move to a smaller set of  items, repeating the process until the culprit is found.
Or you can use Preferential Treatment which is a *FREE* utility that does all the work for you.
Hang in there & good luck!!!!