The plastic front of your computer is the Front Panelhttp://support.gateway.com/s/PC/R/1009566/1009566nv.shtml
Slip this off to access the Power On Button assembly, which has the Power On switch inside it,
-> FOLLOW Anti-Static Procedures -> BEFORE reaching inside, your unplugged from power, computer.
If you do not know, post back in a Comment
Now look at the Rear view of the Front Panel again.
The LEFT Side Panel removes.
Looking at the Rear view of the Front Panel; note that the LEFT side of the Front Panel, is towards the Bottom.
See the three TABS sticking up along this edge?
One at the Bottom, one in the Middle, and one at the Top.
Flat plastic TABS formed out of the Front Panel itself.
Another point of view.......
The metal framework you see that the CD/DVD drive/s are in, is the Optical Drive Bay.
Look at the Optical Drive Bay, and towards the Top/FRONT.
See that flat TAB sticking in from the Front Panel?
Now come down to the Middle of the Front Panel.
See how out at the bottom of the Optical Drive Bay, there is a TAB sticking in from the Front Panel?
See the TAB at the Bottom?
They hook on the metal framework of the computer case.
They go through SLOTS in the metal framework.
The Tabs are pressed to the Inside of the computer case, OR to the outside of the computer case.
This action brings a hooked end on the end of the TAB, to the Middle of the slotted hole it\'s in, and then the Tab is free.
Suggest start with the Bottom TAB, press on it when hooked end is free of slot; then do the same for the Middle TAB.
Now perform this on the Top TAB.
The TABS are pressed to the inside, or to the outside, and pressure is put against them towards the Front Panel.
Push on the Tabs, to push the Front Panel away from the computer case.
Once all three TABS are free, the Front Panel will swing out, and remove.
Power On switch is mounted to this metal case,http://support.gateway.com/s/CASES/GERSHWIN/8016038R/8016038Rmv.shtml
I would open that case, and take the Power On switch itself, out.
Then see if I could find a replacement, or one that I could live with,http://www.ebay.com/sch/i.html?_nkw=atx+power+switch
Direct link to Hardware Reference Guide,http://support.gateway.com/s/Manuals/Desktops/8512041.pdf
Let\'s see if it works.
If not here is the Gateway Support page for it.http://support.gateway.com/s/PC/R/1009566/1009566ul.shtml
8512041 - Gateway Hardware Reference Guide (5-Bay uATX Case)
Go to Pages 37, and 38. (Top of Adobe Reader in page number box)
For additional questions please post in a Comment.