wrong font in hlp-file

When executing "active test" in my word-file and after compiling, the font Arial is converted into Times New Roman. I already had that problem before and found a solution: I downloaded a new dll from the Adobe site (which did not help) and I deletet a Security update for MS Office (then it worked). So the Security update seemed to be the problem. From then on I didn't download security updates for MS Office.
Now, I downloaded three updates for Windows XP and had the same problem, even after uninstalling the three of them the font conversion didn't disappear.
Does anybody have another solution for the font problem?

Thanks!