Windows 7 startup cmd screen flashes by

Check for anything in your startup folder.

Also have a look at Start --> run --> msconfig and have a look at startup there to see if anything unusual is running on startup.

If it's not causing a problem, I wouldn't worry about it.

For the past year or so I had this problem and it finally went away.

It went away when I couldnot access the Internet. My trouble shooting revealed invalid IP address and invalid network. The Uverse repair came out to the house and reset the system. The poroblem was fixed as I was able to get on the Internet. And as an added bonus, the cmd screen upon computer start-up did not come back.

My opinion, and its only an opinion, has to do with the network I was accessing in the past, it was called network2. After the repair, I noticed I now accessed network 3 to get on the Internet. No more cmd screen when I fired up the computer.

I disagree with this. The cmd screen will have nothing to do with your network connection.

Maybe so, but the problem never resurfaced.