hope somen can help me..
Yes, you can. Back up your data, ensure that the computer has at least 1GB of RAM, and buy a retail DVD from the online Apple Store if you don't already have one.
what can i do in this case or what software can i buy to install it correctly and make it run since it has a new hard drive? thanks
it has a new 120 gb hard drive so the installation has to be fresh from scrape i guess.
Correct. The retail DVDs are full installers.
one more question is it going to be compatible no installations errors?
my model is A1150 early 2006 ??
It will be compatible with your Mac, but the possibility always exists that something will go wrong during the process.
Retrieving data ...