While working  VB.Net application(added COM DLL’s references) on 64-bit Windows7 system , i came across a runtime exception like

Retrieving the COM class factory for component with CLSID {632F4591-AA62-4219-8FB6-22BCF5F60090} failed due to the following error: 80040154.

How i handled this error:
-> I just removed the References and added once again.
-> I changed my solution platform as x86, build the solution and my problem is solved.

How to change your solution platform in visual Studio:

select the solution platform as x86 as shown in figure below and build the solution again.

If u did not found x86, open Configuration Manager, 
In configuration manager window, in the list of references you will find platform column with a dropdown.
Select <New..> in dropdown and add New platform x86 as shown in the figure below

Now, Select x86 and Rebuild the solution
Hope it helps.
Thanks for reading, and if you have any other experiences/solutions please share in comment.