You could try using Microsoft Power Toys to Repair Shortcuts

Does the desktop shortcut have the right icon? it should indicate which browser is associated with internet shortcuts.

I know Fruit Bat /\0/\ has already asked but I wonder if you understood what you were looking for: Carefully look at the rightclick menu options and see if about half way down there is 'Open With' which will give another menu to 'Choose Program' then you can make your browser the default by ticking the box 'Always use the selected program'

1. make sure your antivirus and malware programs are up to date and scan you system.

2. then do a windows repair - Repair XP by replacing corrupt files Type

sfc /scannow

in the run box, press enter and let system file checker find and replace missing / corrupt file in windows and explorer.This will take awhile to complete and you may be asked for the CD to be in the drive if windows is not preinstalled on the hard drive.

sfc /scannow problems http://www.updatexp.com/scannow-sfc.html

No need to be frightened

sfc /scannow is a good way to repair the system if it requires it. It will do no harm and may do a lot of good.

problems are only if sfc will not scan or keeps asking for CD when you have a preinstalled system. It will not make matters worse.

I suggested scanning for malware / virues as there is a virus that can affect the right contex menu.

What antivirus system do you use?

septogenarian - there are many older users on this site offering good advice - at least us oldies have plenty of experience to draw on - I'm not that far behind you :0)