Installation problem : no picture/icon on toolbar buttons

Hello,
I 've just installed Blender (2.25 then 2.27) but at the opening, no picture appears on toolbar buttons, but only black square !
I figure out button actions by reading the small text appearing when sliding mouse cursor below it.

Why no icon linked to the buttons ?

Thanks so I can use this appealing program.

Looks like an OpenGL issue of your graphic card.

Provide all data of your system, please and, nevertheless, upgrade your video card drivers to the latest release.

Hope this helps

Stefano

You put me on the right way !!
I had a color display set to 16bits in general display parameter of Windows
I’ve tried to raise it to 24 bits
–> pictures appear in Blender toolbar buttons.
Thanks a lot !
Asta la Vista

Sounds like bad news…

16-bit seems to run much faster than 24- or 32-