X Window isn't running

X Window isn't working.
When I ran

startx

I got an error message as shown in file attachment xwndow.png
Accordingly, I removed /tmp/.X0-lock as reflecting in the attchment.
Then again I ran the command and 2 more commands (shown in the attachment xwndow1.png) but they failed too.
Any suggestion on starting the same.

Judging from the screenshots you're already in an X session thus the error 'Server is already active on display 0'. If you're attempting to start a second session, try this command:

startx -- :1

OK yes
the command you gave worked.
Thanks
Also finally may I know how to switch my operating system from UNIX to WINDOWS and vice-versa? Now, I have to always shutdown and reboot my system to do so. I have both OS installed on my system.