Hier steht
http://www.ptgui.com/support.html8.4. PTGui cannot find the Panorama Tools library (pano12.dll) on 64 bit windows
First of all, you don't need Panorama Tools anymore with PTGui for nearly every stitching job. PTGui's built in stitcher and optimizer can handle the same lenses, projections and more. To convert projects created with older versions of PTGui, choose 'Stitch using: PTGui' in the Advanced section of the Create Panorama tab.
If you do need to use the Panorama Tools library: the 64 bit version of PTGui can only use 64 bit DLLs. Since pano12.dll is 32 bit, you can only use it with the 32 bit version of PTGui. You can download the 32 bit version of PTGui from the
Download page; it will run fine on 64 bit Windows. The pano12.dll should be copied to C:\Windows\SysWOW64\ .
mfg Achim