O/S restoration problem

In the past I had very bad experience regarding data restoration from

NTbackup Full system backup file.

I am using Windows 2k3 & 2K server both.

I am using Dell power edge 6600, 6650 &1850 servers.

When the server OS crashes I used to do following steps

1. First I install OS.

2. Install service pack same as old O/S has & all security

patches.

3. After that restore full backup from tape

But after completion of this when I restore full backup of server

through Ntbackup

Some times server restarts again & again continuously or sometime few

of the services or application of servers not runs properly.

I am restoring from FULL backup set.

At the time of backing up the server there were no file skipped in

report

Where do I m making mistake.

Thanks in advance

With Regards,

Gaurav Mathur