Installing Windows SBS 2008: The nightmare begin

Some week ago, my friend ask to me to reorganize his ICT infrastructure. It was composed by 2 server with windows 2008. One of them has Small Business Server. There was also another server with linux that perform PBX and firewall duties.
This system was build up by me in the last six months, after an upgrade from windows SBS 2003.
Since first installation of windows 2008 I've noted that the OS is very fast compared to its ancestors, but when you install the server softwares, like exchange server, the server start to became very slow.

Now, first of all I've done backup up all exchange data, then I've started the installation procedure of windows 2008. In the meantime I has remembered the first time that I've installed SBS 2008. I've to wait about 20 hours for complete the installation process, so I think that my nightmare was started again.
One of the reasons that have constrained me to reinstall the whole system is that in the first installation, for higher security, I've made up a second server for remote desktop activities and I had installed on it also Active Diretory service. From that moment exchange was become dipendent of the second AD Global Catalog. If I turned off the second GC, exchange has stop to work.
After the installation of the whole sbs 2008, I have started the windows update process. For it I've waited only for about 6 hours.
The server where i have installed the SBS 2008 is a quad core intel cpu, with 8 Giga of ram and a 6 Tera raid 5 disk system configured with two logical disk.
After the automatic update process, I have downloaded the last updated for exchange 2007. While I'm writing, it was the SP3 with rollup 1. I finally after more than 30 hours I have restore the exchange data and I have recreated the system's users. The sever has gone on line after 36 hours from installtion was started.
Now for more than 30 hours I've saw that computer working without do anything but in 36 hours I can install 2 Ubuntu servers fro scratch with all e-mail system perfectly configured.
I've also reed no Internet that other peoples have done my same nightmare.
Now I am sure of one thing, when anyone ask to me to install a server system, I will use only linux.