Sounds like you use AOL.

Re:AOL (Score:1)
by Anonymous Coward on Tuesday March 20, @08:42AM (#352127)
aol has acouple of programs that regularly check the serial numbers of the software you have installed; all that info used to be in a file that got put in the system root directory; Thats why I use netscape. If netscape is doing this, they're at least trying to hide it; The devil I don't know is better than the one I know? Any way, the worst ones are DVD software. There are all kinds of monitoring programs with these, seems like a different version for each, but they all include MS serial numbers. Hell, even my cirrus logic modem has one of these; It puts a file called CLdma.log that has all this info in it as well. This gets sent after install as well, but none of the monitor programs I have show to who. (need better one, I guess.
This is from Slashdot

Now you can decide if you wish to delete it or not.

[EDIT] http://dvdsoft.hotmail.ru/cinemaster.html has the followinf info on CLTEST.TXT.
cinemaster
... CLTEST.EXE (From PowerDVD 1.3 package) Put a DVD disk in the drive, wait for the
light to go off, and run this applet. It creates a file in C:\CLTEST.TXT. ...
dvdsoft.hotmail.ru/cinemaster.html - 78k - Cached - Similar pages
From a google search http://www.google.com/search?hl=&cat...=&q=cltest.txt {/EDIT]