If you have paint in your computer (paint comes by default with windows installation) then copy the file or open the jpeg file in Microsoft paint and save it as TIFF format.

 By clicking on the jpeg file, a window by the name window & fax viewer will get opened (in Windows XP operating system).

In the bottom you will find icons zoom in , zoom out, print, etc... You will also save (copy to ) option, by clicking it you are prompted to a window called save as, where you have the option of selecting tiff format