I'm not quite sure what you're trying to do with these files. Some files, such as jpeg images, are specifically 'opened' by certain software, while others are only 'called' by particular programs.
To associate a file type with a particular program, right-click on one of the files of that type. Select 'Properties'. Alongside 'Opens with', click 'Change'. Navigate to the location of the program you want to open the file with. For example, if it's a jpeg file, choose whatever image-viewing program you use on your laptop. (If you've not got anything suitable, download Irfanview:
http://www.irfanview.com/ )
The other file types you mention are those which are 'called' rather than 'opened' by particular programs. IAF is an internet account file for Outlook Express. You'll only need it if you're transferring account details from one PC to another. (You can create an IAF by going to Tools > Accounts > Export. You can import an IAF by going to Tools > Accounts > Import).
WAB files hold your Windows Address Book. Outlook Express uses a WAB file every time you click on 'Addresses'. Like IAFs, WABs can be exported and imported, so that your can transfer your address book from one computer to another. Unless you're doing so, you can ignore them.
XPI files are compressed files which are accessed by Mozilla software (such as Firefox). Once again, they're examples of files which are 'called', rather than 'opened', by a particular program.
Chris