E-mail & IE Favourite backup

Assuming you're using some current version of Windows (since you didn't specify) Your favorites will be under c:\documents and settings\\favorites. The outlook address book will be an *.oab file. Do a search for that on your hard drive and make a note of where you find it, so when you go to put it back, you put it in the same place and outlook recognizes it. Best way to backup your emails is to export them to a file. You should be able to do this in OE and NM through a File - Import/Export option on one of the menus.

Thank you for your answer Jessie, i tried to look into documents & settings but nothing inside it's empty, I also can't find *.oab file either. I am using Windows ME.

regards
GGK

OK, on Windows ME the Internet Explorer bookmarks should be in c:\windows\favorites. Since this is a system folder, it can have strange effects if you copy the folder, so only make a backup of the files in the folder into another folder and name it slightly different than "Favorites", just in case.
I believe, you should find the Outlook Express files in something similar to c:\windows\application data\microsoft\identities\ and in there at least one folder with {} brackets and lots of numbers and letters in the name.
If you can't find them, search your hard drive for folders that are called identities. Maybe you don't need the "microsoft" in the path. I don't have Windows ME, and I can't access my 98 now. If you can't find the files, please write again.
Note that you will not be able to save your account settings this way - these are stored in the Registry, so write them all down if you are not familiar with the Registry.
As for Netscape Messenger, sorry, it has been 8 years since I last used it :-) Also try the application data folder and search for netscape there.

OLExpress files should be under c:\documents and settings\yourprofilename\local settings\application data\microsoft\outlookexpress

In 2k and xp these are hidden by default.