Upgrading software,only want to keep my i-tunes library.

You were misinformed.

Normal installation mode for Snow Leopard replaces only system files and leaves applications, data and settings as they are.

To erase and install, you have to deliberately erase using Disk Utility on the installer disc.

You should always have a full backup of your system in case of HD failure or serious finger trouble. It would be wise to backup your Tiger system to an external drive using CCC or SuperDuper to produce a bootable clone. That way all your data is safe if anything goes wrong.

I do not recommend using your iPod for this; an external HD is a lot safer.

If you're using a retail SL disc, there is no iLife package with it, so if you want to retain iPhoto, iMovie, iDVD and GarageBand you'd be best to do a normal install.

Ensure you select Rosetta from the custom install list - your older software won't work without it.

The installer will replace the Tiger system files with SL ones and should not touch any of your data or settings. Note that the restart will take considerably longer than usual as files are moved from a temp folder to their correct places in the system.

Caveat; I've done 8 of these now, but two wouldn't install until I erased the Mac HD volume. No idea why the difference, but it does make that cloned backup important.

Be warned that printer drivers, and scanner drivers in particular will almost certainly need updating for SL. That could be a problem if the printer or scanner is more than a couple of years old.

Many third party applications (and some Apple ones) may need updates for SL (Adobe particularly), so check with the vendors for compatability before you upgrade.

There is no Classic in SL and no support whatever for OS9 and earlier applications.

If you still wish to save only the iTunes stuff, just drag the entire iTunes Music folder (iTunes Media in later builds) to your external HD and drag it back to replace the new one after installation. Start iTunes with the opt (alt) key held and choose the iTunes Library from the folder for it to use.

Once again, I wouldn't risk your only copy of the music to an iPod. If it syncs on startup, you risk losing the lot.

A bootable clone is an exact copy of your whole system on an external HD, from which you can boot the computer and work as if on the computer itself.

The applications linked to give you choices about what data to clone, and can also be used to incrementally back up your data from the computer to the clone.

You can make a clone using the Restore function in Disk Utility, but that's all or nothing. Good enough for what you would want as a safety net, though.

You don't have to use the external HD for a cloned system; it can be used just for extra data storage, but if the data is important, it really should be backed up.

External HDs are available from all PC outlets, but some work better with Macs than others. My own backup drives are from LaCie and Iomega. Check the box to see if it says Mac compatible.

A new drive will need formatting for Mac before it's usable; do not use any applications for this which come pre-loaded with some drives (LaCie being one). Use Disk Utility on the Mac to repartition and format the new drive.

Your iTunes Music folder is in your home folder (with the house icon) > Music > iTunes.

Save the whole of that folder and you should preserve your iTunes settings.

I wouldn't trust anything important to the "cloud".

Yes, there are other sources of web-based storage and syncing apart from iCloud.

All I've got time for tonight - meds and bed are calling.

If I can I'll find some more links for you tomorrow (but anyone else who can help, please feel free to butt in) 😎

You have 512MB of RAM (half a GB). You need a minimum of 1GB for Snow Leopard, but more would be advisable.

Your early 2006 iMac will take a maximum of 2GB (2x 1GB cards). This requires removing the existing memory card.

The RAM specifications are; 200-pin PC2-5300 (667MHz) DDR2 SO-DIMM, unbuffered, non-parity (non-ECC). You can obtain Mac compatible RAM from Crucial and OWC/MacSales among others.

RAM is a temporary storage area for applications and files which are in use - it's faster to access this from RAM than it is to have to continuously read it from the HD, which is the permanent storage area.

When you finish with the file or application, the final state is saved to the permanent storage on the HD and the temporary storage in RAM is freed for the next task.

A larger HD (more GB/TB etc) means you can store more data on your computer.

More RAM means you can use more applications simultaneously, and/or get better performance from applications making lots of changes (photo/movie/audio processing).

Your iMac cannot run Lion or Mountain Lion - Snow Leopard OS X 10.6.8 is as far as you can go.

Now I need some clarification.

The house icon only appears next to the logged in account. If you see it in the sidebar when you're logged in and it has the previous owners name on it, it's their account you're logged in to.

Is there another account on the computer (either admin or standard)?

If you erase Macintosh HD prior to installing SL, you'll be taken through the full process of setting up a new account.

You will however lose the bundled iLife applications, because they only come free with the original purchase and are on the original grey discs which you don't have.

It may be possible to change the password from the SL installer disc, but I can't be sure of that. I've never tried resetting a password on an earlier OS version than the disc I'm using.

If you have a seperate admin account of your own, other than the previous owner's, you can delete the previous account from System Preferences > Accounts, but you'll need your own admin log-in password to do that.

The password can be reset without the disc, but that requires entering commands at the UNIX command line in Single-user mode. Not for the faint hearted.