Black window flash at Vista Startup?

Since I got my laptop, I've noticed that when Windows Vista starts and sidebar, etc. is still loading, there is what appears to be a DOS window that pops up and quickly disappears. This is something that also happens on my computer at work when I first logon. They use XP Professional. What is that mystery window?

Also, I started using CCleaner. Is it pretty safe to trust whatever CCleaner is removing from my registry?

It displayed a bunch of NET.framework entries and missing shared DLLs.

Thanks guys.

 

this might help
http://forum.notebookreview.com/showthread.php?t=153286

as for ccleaner just back up your registry. it always asks if you want to create a backup before cleaning the registry. i've been using it for a long time no problems

 

No - the whole screen doesn't flash black - it's a little window that pops up and it looks like a DOS prompt (for the split second I can see it). I'm just curious what it is.

 

ahh. sorry. check msconfig maybe

 

Probably a startup process from one of your programs.. go to msconfig and uncheck all the startup items. Restart and see if it still shows up.. and tick it back one by one or two by two to narrow it down