That is called the "Tower".
Several things can cause this.
First thing I would like to know is if you are bluescreening or just shutting down(due to bad PSU or overheating CPU).
First thing is first, remove what you installed.
If it still happens do the following
When you turn on the machine press F8 repeatedly until you get the advanced boot menu pop up.
Here you will see a dozen options or so.
Code:
[SIZE="2"]Repair my Computer
Safe mode
Safe mode with networking
Safe mode with CMD prmopt
VGA mode
Boot logging
Directory Service mode
Last good configuration
Enable Boot logging.
[B]Disable Automatic Restart on System Failure[/B]
Start Windows Normally[/SIZE]
Select "Disable Automatic Restart on System Failure".
This will prevent the PC from shutting down if their is a blue screen, if their is a blue screen note down the bug check code which is something like 0x000007B.
Their will also be a file name mentioned, write that down too.
Or you can send me your crash dump files via PM, i can see what is causing the issue for you.
The crash dump files are found in C:\windows\minidump\.
Just send all of them, I will find out which one is which.