How To Collate A Set Of .Tiff Files To A .Pdf File Using Pdftk

I know that PDFtk server runs from the command prompt in Windows 7.

Using the command prompt, I accessed the relevant directory in E: using “cd". Somebody told me that what I need to do is type:

But, I see the following error:

convert *.tiff output.pdf (& press Enter)

Please explain in detail as I don’t know much about this topic.