First of all, good upgrade. Windows 2000 is MUCH better than 98. In some ways it is even better than XP.

 

(Some graphics programs have their own option to choose which file types are defaulted to them. Often installing the program will automatically change them. You may want to look at that possibility before the following.)

 

Bear with me, as it's been almost a year since I used Windows 2000.

 

Right click on any file of the type for which you want to change the default program it opens in. See if there is an "Open With" option. In older Windows that was only an option for file types that Windows didn't know what to use, but in XP and I think in 2000, the choice is always there. If the program you want it to default to is not right there as a choice, you may have to browse for it. Once you select the program you want, be sure to check the "Always use the selected program to open this kind of file" box before clicking ok. You will have to do this for each file type, ie: gif, jpg, etc.

 

If Windows 2000 doesn't have the "Open With" choice for known file types, there is another way to do the same thing but it is a bit more tedious. Let me know if this helps or if you need to try something else.