Cant update from 10.5.7 to 10.6.3

I have a macbook3,1 but its very slow. I did remove all the data so taht i can install of upgrade to Snow Leopard.
There are 2 things taht i did tried
Booting from DVD (which is not mine and i think its not for this version of macbook) it shows a stop sing and it freezes there.
The second thing is that i cant update. it starts but it stops, the after a restart nothing have happened.

I cant find the origina 10.5 DVD so that i can format it and then try to update.

Is there any way to fix this problem by not buying the DVDs if i cant find the original one.

 

if you have a 10.6 disc your upgrading with... you just use that, you don't need the 10.5 disc.

if it won't start off the 10.6 disc, try some other bootable discs if you can, to determine if there is something wrong with the disc, or your drive.

 

Well i just opened and cleaned the Lens, the update process goes a but further but if i want to install a fresh copy it still shows the stopping.

I will look for another CD. if not i will try and install it from USB or other external stuff. The cdrom is just making noise.

 

Be patient when it comes to OS updates/upgrades. Apple now does a complete integrity check to confirm the img is good. This can take a long time.

 

Now its fine. i found another DVD and it is running fine

Thnx