I am using Windows XP and all of a sudden, when I clicked on the shortcut to MSN Messenger one day (after starting the computer), it didn’t respond. It seems to be "working somehow" (light indicator showing something is happening and the computer is buzzing) but the Messenger window never shows up. I have uninstalled it several times, rebooted, installed again, but to no avail. I have also removed the shortcuts and created new ones. Nothing seems to work. The process is running though – msnmsgr.exe. I don’t know why the computer started behaving this way. I have an antivirus, don’t go to any suspicious sites, etc. Also, quite recently, my Firefox stopped remembering and suggesting form entried used in the past although it is set to do so. Is it possible that my Windows XP need reinstalling or so? I have had the computer for 2 years. I have a RegistryCleaner that I use from time to time (and have used it now again with no improvement) that always finds lots of errors, etc. and fixes them. (Although I suspect it is quite possible that the registry cleaner may have caused some mess too.) If you have any suggestions, I would be grateful. Thanks a lot in advance.
Adding some details:

Thanks, I have done so and all went fine. Except for the fact that it has not solved my problem, unfortunately. I have tried installing it, uninstalling it, cleaning the registry, etc. and all in vain. I have really no idea why it is doing what it is doing. All of a sudden. Any other idea? Thanks a lot in advance.

Okay. Let me tell explain what happened. First, I installed MSN Plus!", and then the Windows Live Messenger was acting strangely, like It’ll close by itself automatically for a few minutes, but when I try to open it again, It won’t open; I have to restart the computer to sign on. Then, Second: I tried to Uninstall the "MSN Plus!", but nothing changed, so I tried to Repairing the Windows Live Messenger, but nothing changed as well. So I had to Unstall the Windows Live Messenger, but it says It doesn’t exist, when I go to Add/Remove Programs, The Windows Live Messenger Icon is there, but the software isn’t. Finally, I tried to install it again, but it tells me that you already have Windows Live Messenger installed, then I tried to install the Beta Version of Windows Live Messenger, and tells me the same thing. I don’t know what to do. This is the first time happening, and I don’t want to restart the whole harddrive just because of a software. So Please Help. Thank You

I’ve recently got a new computer, HP Elite Intel Core i7-920 2.66GHz Desktop Computer. The day i got it, and got it all plugged in, it crashed. For the beginning it was fine, browsing internet, going on msn, surfing the web, etc. all of a sudden it freezes on me, the mouse works and so does the keyboard. however the screen wont let me do anything, therefore i had to manually shut off. I figured the problem was registry corruption. I tried reg-cure and was not able to run it for my computer had a Vista 64bit premium home edition. So i used CCleaner and all worked well. After a while, my computer freezes again, this time i left it idle, and it was in screen saver mode. When i moved my mouse to return to my desktop, the screen freezes and this time so does the mouse. After waiting a bit, i got the blue screen of death. So i turned it off again, and all.. To make a long story short, My computer keeps on freezing for no reason during web-browsing/doing nothing/screen saver/gaming/ etc. Occasionally i would get the blue screen of death, Sometimes from the freeze or for no reason. I have tried Registry clean up, and it still happens. Any tips from people who keep they’re Vista from crashing would help.
I dont believe its any virus or spyware.

I recently had my computer system swiped clean, but I am on dial-up through msn, so when I insert my disk to download Msn it is saying no modem detected, What does this mean? I have it all hooked up right and my other computer is working fine with this phone line. Can someone help me out?