Mac mini 2007 Intel Core Dou Intall problem

I have an Apple Mac mini (2007, Intel Core Duo), with Mac OS X Leopard (10.5). I installed this software via the original installer DVD, but i could intall combo update (it downloaded it, and after restarting it stops on the blue screen with the blue loading line [but it didnt load], it tried to install allnight long), and Snow Leopard (10.6) also.

Hardware Overview:

Model Name: Mac mini

Model Identifier: Macmini2,1

Processor Name: Intel Core 2 Duo

Processor Speed: 1.83 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 2 MB

Memory: 1 GB

Bus Speed: 667 MHz

Boot ROM Version: MM21.009A.B00

SMC Version: 1.19f2

HD: 80 GB