I installed OpenSUSE in my old PC (like 5 tears old), and it worked fine -even now it works fine. I choosed the Gnome desktop but one day I booted up I found that no window had controls anymore, I mean, I cannot re-size, nor move a window, close it, maximize it, etc. All the controls are gone.

At first I though it was because I was messing around with desktop effects, but didn't find a way to make the controls re-appear. Please note that the controls didn't dissapeared during this process, they were gone (along with my wall-paper), some time later, when I booted again my PC.

Please help me. I'm very curious but tend to mess with thing like this and I'm just getting to know Linux.

Regards and thanks in advance!