I've some problems installing the Din font in different versions: Regular, Medium and Bold.

All styles are listed under the same font name on Windows Font utility, but Adobe Acrobat XI Pro recognize only the first style installed.

For example, if I install in this order Regular, Medium and Bold, only Regular font is recognized.

If I install in this order Bold, Regular and Medium, only Bold font is recognized.

All suggestions are welcome.

The font indeed has problems with names/styles. You can fix it with font utilities like e.g. DTL OTMaster or Fontlab TransType.
I have attached the result from TransType 4.

Many thanks for the modified fonts !!!

They now are working fine.

What exactly should I do once I get TransType 4 to achieve the same result with fonts that have a similar problem ?