how can I fix the arabic letters ?

2 Possibilities:

+You are trying to do Arabic in MS Word for Mac, which is not possible. Use Mellel, TextEdit, Nisus, or OpenOffice instead.

+You are trying to use a Windows Arabic font. Switch to an Arabic font that comes with your Mac, like Geeza Pro.

Sam.Fisher wrote:

my font is the Mac OS default font, I see it in opera it was "times 16"

You cannot use that font for Arabic. As suggested before, set the font to Geeza Pro.

I'm not used to Tiger yet, but I think this will work for you.

1. Open system preferences

2. Goto "international"

3. Click "Edit List..."

4. Click the checkbox next to Arabic [You will have to scroll down]

5. Make sure arabic is at the top of the list on your left.

6. log out and back in.

I'm not sure if this will work, but I'm 99 percent sure it will 😉

PS If at all possible, I recommend you upgrade your OS, which is essentially 7 years old, which is ancient in computer terms. It is hard to find anybody still running that to get help when problems arise, and various improvements have been made in Arabic text display in the meantime.

Sam.Fisher wrote:

Actually, all the tab panes in opera are still seperate, my question is , how can we change the system font with Geeza Pro instead of change that for each application?

You can't do anything about the fonts used by OS X.

Ask Opera support and try Firefox, Chrome, or Safari instead.

Have you tried another browser? Opera is the least common one...

Find your exact powerbook here and I think it tells you the maximum OS:

http://www.everymac.com/systems/apple/powerbook_g4/index-powerbook-g4.html

But that machine is too old to bring you very close to current technology, which is 10.8 being released this month.

Sam.Fisher wrote:

it changes just the opera content !

Setting the font to Geeza Pro certainly also fixes TextEdit and OpenOffice, doesn't it? Exactly what apps still have a problem?

Sam.Fisher wrote:

so I think the tiger 10.4.11 is the best choice for it, doesn't it?

Yes, that is latest version of OS X which will work with that machine.