Reinstalling Mac OS

Hi Jay.d;

Generally, if you add junk to your Mac and it slows things down, all you have to do it put them in the Trash and empty it. For the vast majority of the things you can install that is all it take to get rid of it.

This is very much unlike Windows where each and every installation adds entries to the Registery and the only way to clean that is a reformat and reinstall. They is nothing like that in Mac OS X so there is no need for periodic reinstalls. In the four years I have used Mac OS X I have never had any reason to reinstall the operating system.

Generally, slow downs can be fixed without going to such extremes. What hardware do you have? How much RAM do you have? How much free disk space do you? If you will answer these questions for us, we might be able to come up with some ideas to help you short of a reinstall.

Allan

What junk have you added to your Mac?

Unless you have limited free hard drive space, this should have no or minimal effect on slowing down the computer and re-installing OS X should always be performed as a final last resort. OS X is not Windows.

As a first step, check Resolving Disk, Permission, and Cache Corruption for system troubleshooting procedures and when doing so, follow all steps/instructions in the order provided.

See Maintaining Mac OS X for recommended maintenance for OS X which isn't much.

Regarding having adequate free hard drive space, see Problems from insufficient RAM and free hard disk space and Tuning Mac OS X Performance may also be helpful.

Regarding re-installing OS X, your options are Archive & Install or Erase & Install.

Selecting Erase & Install will re-install OS X as indicated. The hard drive will be erased first and OS X and all software included on the install package that shipped with your Mac will be installed new. When completed, this will be the same as when first turning on the computer when new.

The Archive & Install method will re-install OS X new and the previous system will be archived and saved as a previous system folder. You cannot boot the computer from or use the archived previous system folder to run the computer.

There is also an option to preserve user and network settings and when selected, all user and network settings along with all user data and 3rd party applications will be transferred to the new system. After confirming all user and network settings, user data and 3rd party applications were successfully transferred to the new system, you can (and should) safely delete the archived previous system folder.

See General advice on performing an Archive and Install.

The Erase & Install method definitely requires creating a backup beforehand but you should do the same before using the Archive & Install method.

To boot from the Tiger install disc, insert the disc and re-start the computer holding down the "C" key until the computer boots up from the disc.

As previously provided, re-installing OS X should not be necessary and should always be done as a final last resort if all else fails.

i installed a firewall/virus/spyware program, which wouldnt uninstall.

Which program? This type of program likely includes an uninstall function and if so, it should be used.

You don't need 3rd party Firewall software with OS X. OS X includes a built-in Firewall which is substantial so no other Firewall software is required or needed.

See Uninstalling applications.