GIMP :: Windows 2.6.11 File / Open TIFF And JPEG Not An Option

I have installed both version 2.6.11 and also version 2.4.7 of the Windows version of Gimp that I have downloaded from here [URL]

When I launch Gimp, and select File / Open from the main menu, neither TIF/TIFF nor JPG/JPEG files are listed when "All Images" is selected in the file type drop-down listbox. If I select "All Files", and then select either a TIFF or JPEG file, then an error message appears stating "Unknown file type". The specific types listed in the file type drop down list box include:

GIMP XCF image (*.xcf)
bzip archive (*.xcf.bz2, *.bz2, *.xcfbz2)
Dexktop Link (*.desktop)
G3 fax image (*.g3)
GIF image (*.gif)
gzip archive (*.xcf.gz, *.gz, *.xcfgz)
Photoshop image (*.psd)

I have read here: [URL] that, "Some of the file types, such as JPEG and TIFF, require extra libraries (described elsewhere)." I have no idea where "elsewhere" is.

I have completely uninstalled, rebooted, and reinstalled both version 2.6.11 and 2.4.7 with the exact same results each time. The program otherwise works as advertized, with no errors or problems that I am aware of.

Am I missing something here? All indications are that GIMP (Even the Windows version) natively supports TIFF / TIF and JPEG / JPG files, but that is certainly not my experience!

I am specifically interested in opening TIFF / TIF files.