I saw the adobe pdf viewer control in vs2010 toolbox somewhere.
and I thought it can be very useful.

So I tried to add it.

http://img155.imageshack.us/img155/3349/choosetoolboxitems.jpg

as I expected things are never simple for me,
when I try to drag it to the form. there'a an error.

http://img214.imageshack.us/img214/8042/errorrp.jpg

any idea experts ?

It opens up file in abode pdf reader.
I wanted to have a PDF viewer in form.

Also do u know any website where I can download various vb.net controls ?

If you need to display a PDF document without the use of any plug-ins, try rendering each page to an image format like JPEG or PNG.

Converting PDF documents to Flash SWF is another solution that seems to work well for the web. Scribd provide a document sharing service that does this, and there are others, so it's worth looking around.

If you want to cut your own in VB.NET, the documentation for ABCpdf .NET includes a freely adaptable project which you could use as a starting point. See example projects > swfexport.