OK
It would have been better with a game going but mute now as you are going to do the rebuild.
This is how I would proceed. Remember to disconnect the power and take anti static measure.
Remove the graphics card.
Make a note of which SATA socket is used to which HDD and Optical drive.
Disconnect all cables except the CPU fan.
Remove the MB.
From the
old case, remove the I/O shield, it pushes
into the case, remove any fans if you want to reuse them in the new case.
If the new case has a I/O shield installed, remove it and
replace with the one from the
old case. install any addition fans.
Important. Make sure the stand-offs in the new case match exactly the pattern and number as in the old case.
Install the PSU.
Transfer the HDD, Optical drive. Any other, like card reader of fan control.
Install the MB.
Install the GPU.
Connect the main cabling, MB, (2 cables) GPU, HDD, Optical drive,,, refer you note for SATA ports. fans.
Connect front
USB 2.0, and sound.
If you have a mini internal system speaker, make sure the +/- on the plug match the +/- pins on the front panel header. Connect the other front switches Power on, reset, HDD activity.
Connect the keyboard, mouse and monitor.
Check over your wiring.
Connect the PSU switching on at the socket and the back of the PSU,
Switch on the monitor.
Press the power on.
If you have questions or problems, please post.