Not seen this kind of problem reported before. I would try:
Right click on a photo, click on Open with on the opening menu. Click on
Choose program on the opening list. Click on Picture and Fax Viewer on the
opening list and check the box "Always...."

First, the order in which the images appear in a slide show are a
property of the displaying software.  Most software will default to
alphabetical order by filename, but some can be change to display
in time order by file created/modified date/time.

Your dad's machine has Acrobat associated with the .jpg file type, so
it uses Acrobat to open .jpg files.  Your computer has another viewer
associated with .jpg files, and uses that.

When they are installed, many programs change these associations to
point to themselves for some set of filetypes--only *some* programs
ask you before they do it.  ;-(  This is done "for your convenience",
but for most people, changing the association of an already-associated
file type is an unwanted hijacking of the file type.

You can change the program associated with opening a file by changing
the file type associations.  One way of doing this is by opening Windows
Explorer (the file explorer) and click on Tools, Folder Options, then
the File Types tab.  Then scroll down the list of registered file types
to ".jpg" and change the "open" association to the viewer you prefer.

-michael

Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it is seriously underused."