Lost file associations

I have a computer running win98 that will not associate .jpg files with a program to open them in. I have tried to reassign the association but every time i try it says there is already one created. yet I can not open any of the jpg files. I have been through every one of the associations and can not locate the one that the computer says is for .jpg. IS there anyway to recreate the association or at least fine the one that the computer says exists or am I going to have to reinstall win98

Simon