When I start my computer it starts in DOS
DOS Loop at startup
TYPE exit At the command prompt
The system should boot to windows ..
Go to start shut down choose to restart
This should clear the issue up .. if not you maybe in a DOS loop ..
From the command prompt type in
REN config.sys config.old
Hit enter
Then type in
REN autoexec.bat autoexec.old
Hit enter
Type EXIT
Hit enter
The computer will reboot to windows