VS2010 opens website in notepad? bad hotfix?

Question

I am using VS2010 on Windows XP pro (sp3, x86), and I just installed the hotfix kb2106584. This fix was reported by some people, example here, as having a fix for an issue I had with Asp.Net Development Server not getting opened properly from VS, which I was having previously. My issue was being caused by ESET NOD32 messing with the http traffic from devenv.exe and causing all the ports in my computer to get used up, however.
Anyway, as soon as that was finished, I opened my website back up, and clicked debug. Asp.Net Dev server pops up, which was what the hotfix was supposed to make happen, and then notepad++ opens with the tabs I had last time I used it, and IE never shows up. "Wait, what?" try it again. and again. Always notepad++, never IE, always with no new documents opened, just some completely unrelated stuff.
I've seen one other post on SO about this happening, here, but his issue was corrupted files/filesystem. My project is in source control, so I tried a delete&revert to yesterday's revision. Still opens notepad++, so that's not my issue.
I've also tried rebuilding, which did nothing, and deleting my local Solution files, which also did nothing. I restarted the program and then the computer, both to no avail.
I start to believe that this is the hotfix screwing things up, so I try to do a system restore to a couple days ago. Once again, no dice; it's still pulling up notepad++ instead of IE.

So, the questions become:
Is there a setting or two I can try changing to make it open the proper program again?
Or was this a bad/improper hotfix, and if so, how do I uninstall it? It doesn't show up in the Add/Remove Programs dialog, and I don't see an option to uninstall it in VS, or in the installer.

Thanks in advance.

[edit] Also note: Notepad++ is not actually opening the website file, it's just getting opened with whatever I left in it last time. I dunno if this helps at all, but I felt like details would be appreciated. [/edit]

Answer 1

Fixed:
Uninstalling n++, deleting EVERY registry entry & folder containing 'notepad++' (except one, from whose string I removed ";notepad++.exe"), then reinstalling n++ made VS stop opening notepad++.
Now it opens the default web-browser again.

[edit]
Note for anyone else out there who ends up with this specific and bizarre problem:
It would be worth a shot to try changing the "Browse With..." setting in VS, by r-clicking on Default.aspx to "Internet Explorer". My list included Notepad++ as an available internet browser.
This might be a better solution than the previous, if it does in fact work.

I didn't know this setting would allow Notepad++ as an option until I had to set it back to IE again after all this, and that may have been the problem all along. Apparently, VS just changes this setting sometimes. How or why N++ got put in as an internet browser is completely beyond me, but I did myself the favor of 'Remove'ing NotePad++ from the list, and you may wish to do the same.
Again, I'll never truly know whether or not I nuked everything when I could have changed a single setting that got mysteriously reset, but may this [lesson?] at least be recorded for posterity.
[/edit]

It took all of that to figure out that it [was?] a bogus registry entry somewhere that [may have been?] modified by the hotfix; a registry entry that neither notepad++ nor visual studio 2010 ultimate would clean up on uninstall or replace on reinstall
Which was it? I have no idea. Like I said, I didn't even use n++ this week until VS started opening it for me, and the only change I made was to install that hotfix.