my laptop became lag after i upgrade my OS X

Please go to  Menu > About this Mac > and tell us Version, Processor & Memory specs on your Mac. Also available hard disk space, by choosing your Macintosh HD and "GetInfo" (cmd-i)

to really solve the problem , and if you have an afternoon off .

1.make backup of your system

2.Erase Macintosh HD

3.Install new mac os X

4. Migrate data back with migration assistant.

5. issue resolved

You will take all errors out of the os X with this and will have migrated the data back.

Cameron.

Try starting in Safe Mode and see if the problem still occurs?

Restart holding the "shift" key.

(Expect it to take longer to start this way because it runs a directory check first.)

If this works look in System Preferences > Users & Groups > Login items and delete any third party login items (-), you can always add them back with the (+). Also look in /Library/Startup Items. Nothing is put in that folder by default, so anything in there is yours.

Cameron's solution would probably be the best. But you might try just re-installing the OS "in place" before you go that far.

Boot up holding command-r keys into your Recovery Volume.

The screen should give you these choices...

Restore from TM backup

Reinstall Mac OS X

Get help online

Disk Utility

First run Disk Utility Repair Disk, if you get errors run until no errors reported or reports "the disk cannot be fixed". Then, choose Reinstall OS X. This will be an install "in place" and shouldn't effect any of your own data or settings.

hello

I too had a similar problem so i contacted the place where i got my imac. The engineer clean installed the 10.8 os. I feel that the issue lies in 10.8.2. Try a clean instal and see. Now its zippier than before.