Reinstalling mac OS Help

I would like to reinstall the OS on my mac because it is running really really slow! Could someone point me in the direction of a good guide of how to do it?

I am running OSX 10.8.4 on an early 2011 Macbook Pro
2.3ghz i7 processor
4gb Ram

Ta

I’ve just done it on a Mac Mini but not sure which version it was running.

Restart it and hold CMD+R. This should take you to a screen that allows you to reinstall OSX. With my mini it allowed me to download a fresh version of OSX off the Apple server.

Hope it helps.

First make a back up or two of your data

How full is your hd ? Full disk makes machine run slow

Have you installed other programmes like google drive for mac ? Some of these programmes make machine run slow

As above you can download a fresh os from web but first you should make a data backup via time machine or a clone

Have a look at macrumours forum

Get some more RAM.

Get some more RAM.

Hold on a second …

I have a 2009 mac mini which had 2gb ram and 160gb hard drive – it was the full hd which slowed it the most. I have upgraded to 8gb ram and 750gb (quite easy) but as above I would check hd first and see if a purge of redundant data files helps (eg old files, also iPhoto makes a copy of pictures imported so you may have two copies of each photo if you imported from hd rather than direct from camera)

You shouldn’t need to reinstall the OS.
Try running Onyx, applejack or just use disk utility to repair and verify permissions.

cheers for the pointers guys, i spent a few more hours researching this and found a few more ways to speed up/clean up the mac…. some of which are mentioned above. It seems to be running better now but essentially i’ve ended up buying more ram.

I have found that the main culprit for slowing down the computer is the web browser all three: firefox, chrome and safari use over a gigabyte of RAM with say around 8 tabs open and I dont have any plug-ins or extra crap running thats just the bare version downloaded from the net, PITA really but more RAM should sort me out… If I am feeling adventurous I may upgrade to a SSD at some point if it continues to be slow!

SSD makes a pretty big difference to boot times etc, and if you’re doing lots of read/write. However if applications like firefox are slowing things down then RAM is probably all you need. Flash is pretty good at killing performance on most OS’s IME, and this site is one of the worst (or perhaps I just spend too long here so notice it more).

If it’s a 15″ model, you’ll get 16GB memory in it.. which should sort most memory problems :).