IMO the issue is more of you not using the right screw head on screwdriver.
I can't tell what kind of screw it exactly is, but looks to be either Philips PH0 or PH1.
From right side, 3rd or 4th:
If you do use incompatible screw head, you'll round the screw, where only fix would be drilling the screw out. But that, most likely, will drill hole to MoBo (PCB) underneath it as well, if you go too deep with a drill.
Screwdriver head must have snug fit with screw. Any play means too small and when it doesn't bottom out, it's too big of a head.
Oh W40 may short circuit things, since it's conductive liquid. And i doubt that you can apply it without flowing to MoBo (PCB).