How do I resolve "BadImageFormatException: Could not load file or assembly" on x64 & .NET?

Q: I am interested in PDFNet SDK but I cannot seem to load pdfnet.dll
assembliy. The error I am getting is:

BadImageFormatException: {"Could not load file or assembly 'PDFNet,
Version=5.0.1.0, Culture=neutral, PublicKeyToken=36167be3f67ac39c' or
one of its dependencies. An attempt was made to load a program with an
incorrect format."}

I am running Windows Server 2008 x64.

Please advise on how I could make this work in my environment.
----------------------
A: Assuming that you are running on Windows Server 2008 x64, please
use the following steps:

a) In case you do not have VS2008 installed you need to make sure that
standard VC 64-bit runtime is available. You can download VC 64-bit
redistributable using the following link:
http://www.google.com/url?sa=D&q=http://www.microsoft.com/downloads/details.aspx%3Ffamilyid%3DBD2A6171-E2D6-4230-B809-9A8D7548C1B6%26displaylang%3Den&usg=AFQjCNF5MKJri5MgxJi1Xjc5ug6DhQcYMg
or search for "VC 64-bit Redistributable" on the Web.

b) Download: PDFNet for .NET 1.1.-3.5 (64-bit) :
http://www.pdftron.com/downloads/PDFNet64.zip

c) Extract the archive and open any sample from the Sample folder
(e.g. PDFDraw sample).

d) Run the sample.

Based on the error message it seems that you are either using a wrong
DLL version or that VC 64-bit redistributable is missing.

Btw you can also run 32-bit version of PDFNet on 64-bit machines if
you change the 'Platfrom Traget' (in the project solution - located
under 'Solution properties' > 'Build' > 'Platfrom Traget') to x86.