Most likely the problem is that the PDF file does not have Arial Unicode MS Bold embedded although text within the PDF file is formatted using this font and that unlike some previous versions of Microsoft Office, recent versions of Office that are compatible with Windows 10 include neither Arial Unicode MS Regular nor Arial Unicode MS Bold. The last Microsoft product to include Arial Unicode MS Regular was Office 2010 which did not include the bold version of this typeface.
To confirm that the font is not embedded within the PDF file, open the PDF file and press Ctrl-D. Open the Fonts pane and scroll down looking for Arial Unicode MS, Bold. Next to the font name, it should not say (embedded). That would confirm that the problem is due to the font not being installed on your system.
The problem is that Arial Unicode is a font that support a large number of glyphs and encodings. The normal substitution fonts within either Adobe Reader or Adobe Acrobat cannot provide substitutes for most of the characters supported by Arial Unicode.
I suspect that one way or another, your older computer had Arial Unicode MS Bold installed, although it was not installed by either Windows, Office, or any Adobe program. There is no such program as “the Adobe Writer program,” but if you are really referring to Adobe Acrobat, the answer is that “no, that program won't solve this problem.” You need to license and install the font on your system.
- Dov