Having trouble installing Leopard

I have an handed down Mac G4 from my dad, it was freezing alot (it had OS X 10.4.2). So i decided to reinstall OS X, unfortunately the copy of Tiger has disappeared so i had to reinstall OS X 10.2.8 .... i know i know. So it worked fine after that, til i decided to buy Leopard.

When i do the install it, it gets through about 15% of the install and stops saying "could not validate "ESSENTIALS", please contact software manufacturer". Anyone else here had this or similar problems?

I have googled it and alot a people have had this and similar issues, ranging from a defective Leopard disc to aftermarket RAM AND HD's. I used the disc utility function and verified both the permissions and the HD itself, also repairing them, it says the HD's are ok and ready (i have two). I even flashed the drive and tryed with same results.

Any Mac wizards out there? If still pretty new to them.

You may have to Partition the disk. You will lose all your data when you do this, so back up before you do so. But before you partition and potentially lose data try to repair the disk permissions from the Leopard (10.5) install disk.

Insert the installer disk, when things are up and running, click agree, then you will see a utilities menu go to it, and then select disk utility.

Select your drive (usually Macintosh HD), and then click repair disk permissions. When that is done you might as well run the disk repair as well, and make sure the drive structure is good.

Once you have completed those steps quit the disk utility and then try to install the OS.

If that does not work go back to the disk utility, and select the volume or drive, not the partition. Then select partition. Rename and repartition the drive. If you are running 10.2 I highly recommend only running one partition, and if your hard drive is under 100GB I recommend only running one partition. OSX is too virtual memory dependent and slows once the boot drive gets over half full.
After the partition, quit the disk utility and partition the drive.

Ok, i have flashed the one drive and did the permissions and repairs, it says its fine, however i havent tried the rename. I was told by a "mac guy" from my dad that there might still be a "legacy" or remnant of the old operating system. Should i flash both drives and partitions, rename and try?

Thank you for a response i was starting to lose hope, dont wanna have to take it to apple or a shop, plus Leopard was kinda expensive, hope it wasent a waste.

K i did what you said and even exchanged the OS disc for another one. With the same results .... i have read on the internet that is may have something to do with the ram, i am gonna take out the aftermarket ram and try.

This is driving me insane.

The older Macs were very picky about ram. Get some good ram, and try installing.

What G4, and can you post an apple system profiler file?

why are you isntalling leopard on a G4... tsk tsk.. its basically huge in its requirements.

Its decently equipped. Stock 1.6 GHz and over a GB of ram. With 2 75GB hard drives, it was used for prepress work in my dads printshop. How do i get the system profiler file.

Apple menu > About this mac > more information > file > save as

Ill post that soon. One more thing to knock off the list, i took out the aftermarket (Samsung) RAM and it still did the same thing, so i know now its not the ram.

is that G4 a dual processor machine? if you are adding the GHz from 2 chips that could be your issue. what are the full system specs?

Leopard will NOT under any circumstances install on a machine with less than the min requirements. when you swapped the stock ram back, how much was it?

Stock ram is 1024MB, well i assume it was 512, since it has 2 512MB chips. But they are the same make. Its only a single processor, according to my dad this is the newer of the 2 G4's he had, the older one had 2 processors but wasent much faster and not as much RAM.

Ok i know this is old but the problem in fact was the RAM. If this same thing happens to you, this is the usual culprit. Had to change it all out.

I hate leaving my threads unanswered. So there ya go.

the iPhone has more usefulness than a G4 paperweight

Be nice.

i was.

Lol what can you expect from a hand-me-down from a pre-press room. It fills my need, all i need it for is internet, downloading, storing pics/vids and the like. Dont game so its not a big deal. Free is free.