[Fisneaky]

did hear of this fix for folk that "lost" their HL buttons.

For Vista or Win7 users;
Go into your HL folder and look for the program's "skins.ini" open it with notepad and change all entries using three "dots" i.e., "..." (without the parenthesis), to ".." (two dots).
This restores the appearance of the HL GUI so that the buttons are once again visible.