With MS Office 2007 or 2000 just open Outlook and the setup window appears. Probably the same for other versions. Follow along and at some point you will probably be asked if you wish to make Outlook your default mail handler.

Is it possible you have reset the mouse buttons? Right click usually brings up a small menu window. In the case of IE you have options including delete and Properties, clicking Properties then Details followed by Message source gives one the opportunity to read the email by using the back door so to speak. It does not open the email going this route.

I have never heard of an ISP that told you what to use as your email address. Are you talking about your ISP when you say your provider or something else? When I set up our comcast I set up an email address similar to what you are saying with some initals and part of the name. I never use it but set it up just in case I should need one and to get any correspondence from comcast should they email me. I later decided to tie that email account to my ebay account and ebay came back and said that email address was already in use by someone. HUMMM well how can that be? So I created a different one at comcast and used it. Fast forward to last week when just for the heck of it I decided to go check on those comcast addys to see if there was any mail. Well that first one had a ton of spam in it and several emails from someone with the same initals/name and it looks like he also has that same email address. It has not been an issue for me since I just do not use that address but I was able to open all those emails of his and they were business related and some were legal. I am sure he would not be happy about that I know I would not be happy. I have no idea how comcast let that happen, each email address should be unique and never be allowed once someone has locked it in. the other 2nd comcast one I set up and ended up tieing to my ebay had zero spam and only email from ebay in it. very weird and sounds like maybe something very similar is happening in your case. If so the ISP should be able to check those 2 accounts and see why exactly that is happening. Definitely check your full headers and get all the routing info and let them have that info so they can sort it out. you may have to ask how to show full headers each email client is different, I have not used outlook express in ages.

I'll take a guess just for fun.... Click Tools > Options > Connection > Setup (Starts the Wizard) > Next. This brings up a choice of 4 options. The one chosen should be 'Connect to the Internet' If not then choose it and complete the wizard routine.