This issue has been discussed several times on the forum. This problem can be caused by these things:
1) A product you installed, which very invasively attach itself to *any* executable in your system. Something like that shouldn't be used at all (it's a full hack into your system), and we know for sure the freeware ATI Tray Tools does this, but even if you don't have installed it (are you really sure ?), it doesn't mean much, the ATI Tray Tools utility is the one we *know* about, but there might be others out there that we don't know, which work with a similar principle. Removing anything from the Tray bar is not a sure fix, it would eliminate only the programs that create an Tray bar icon, but those that don't.
We also got report that a power management related utility for some laptop do this.
A better way to check everything at startup is to use the MSCONFIG utility (just type MSCONFIG in the Search bar and press Enter), so you can select what is being loaded at start. And, of course, reboot to apply the changes.
2) If it's not a product you installed, the only other thing that can do this...it's a real virus.
The only thing sure, the problem doesn't have anything to do with GSX and can't be fixed by us, because it's caused by something else which is ATTACHING the Couatl.exe (and likely, any other .exe in your system, so it's very dangerous)