An upgrade from Mac OS X 10.5 to 10.11 – Leopard to El Capitan – is a big leap, but if your Mac has languished because there never seemed to be a reason to update it, this leap might be what is now required. You will otherwise be finding that many webpages do not work, and it will be a prerequisite to further upgrades.
If it does, there also are some extra considerations worth thinking about when performing an upgrade from Mac OS X 10.5 to 10.11:
- You could do as Apple
suggestby upgrading to OS 10.6 Snow Leopard first. You need to get a Snow Leopard installer disk to do this. They are sold by Apple, on DVD, and available here: https://www.apple.com/shop/product/MC573Z/A/mac-os-x-106-snow-leopard.
- You could boot the installer and use Disk Utility from the
Utilitiesmenu to reformat the Macintosh HD hard disk in your Mac so that it no longer has any system, and delete all your data. Then the El Capitan installer will be able to install a clean install of El Capitan. So if you are going to do this, back-up your stuff first, so you can put your data back after the upgrade.
- Or you can fool the installer into thinking your 10.5 system is 10.6 using the following instructions. Remember, this is a hack. No upgrades are guaranteed to be successful, and ones with a hack involved are less likely. But I have used this hack more than once and all has gone well.
1] Navigate to Core Services
Navigate to the /System/Library/CoreServices folder.
2] Edit SystemVersion.Plist
Using a text editor that lets you edit system-level files, open SystemVersion.plist.
Locate the line with the ProductVersion key. Just below it is a string of characters indicating what OS you are running. Your number might look something like 10.5.8, signifying you are running OS X 10.5.8.
Change that number to 10.6.8, then save the file.
3] Restart Your Mac
Lastly, shut down your Mac and restart it, booting into the installer disk by holding down the ALT key.
El Capitan is more demanding than Leopard, so make sure you have as much RAM as you can in your Mac. Also, consider getting an SSD to replace your disk if it is a mechanical one.