If you use Windows 7 32 bit.. and you use Pro Tools m-powered.. you've probably gotten the 0xc0000005 error. It's the same error people used to get also when you would have Internet Explorer 8 on a previous version of windows.. you used to be able to fix that by uninstalling ie8. You can't uninstall IE8 on windows 7, and disabling it (through the add/remove windows components) doesn't count.
someone put out a fix as a .reg file that works. I've went through the .reg file and found a lot of spyware URL's, so I cleaned it up a bit, and if you need the fix, I've reposted the clean verison on my website blog:
MooN sHizzLe Productions OFFICIAL WEBSITE v6.0 :: Blog :: Black and Blue Ink.’s Lyricist Manifesto, “Left Hook,” and The Pro Tools M-Powered 7.4 Windows 7 Fix
Link is the second line in the entry.