I finally got a copy of Win98se, I want to install over my existing Win98 1st ed.

Questions:

1) Can I just install over the existing 98 (i.e. will it overwrite) ?
- if so will it save my personal files ?
- if not what is the best approach to accomplishing this ?


I know the easy answer is to copy my files 1st, but I don't even know all
of them, and I have some additional programs I'd like to keep like MS access ..