I have the exact same problem (XPS M140 system, running XP Pro)... I have spent an hour or so researching ways to fix it on about 3 separate occasions and come up with nothing! Also, I got brave enough to click the (blank) buttons, somewhat at random within the InstallShield program and none of them seemed to do anything. I know I have never installed the InstallShield software or any updates to it personally, that Dell includes software on many of their machines that use the software to update, and that my particular version on InstallShield has had this [problem] since the first time I saw it appear on my screen almost a year ago.

 

-Chris