... said a Korean ad banner. Means:
If your computer acts weird, (let our program) inspect it first!
Unfortunately, the contrast between the letters and the background was way too low, so I accidentally read it wrong, and had to go OTL:
컴퓨터가 이상할 땐 우선 검시해 보세요!
While 검사 (GeomSa) means
inspection, 검시 (GeomShi) means
autopsy, which made the above sentence mean:
If your computer acts weird, (let our program) perform an autopsy on it first!
... A computer coroner... orz