how to use unix or linux on window7?

i would like to write shell script but I use window7 then how can I test and run it?

Probably the easiest is to install UWIN from AT&T Labs--Research:

www/uwin/uwin.mm mm document

You could also install a virtual machine environment (e.g. virtual box) and then install Linux or FreeBSD in the VM environment and do you testing under the real OS.

Yes, sorry, I am so newbie on this. I used to run shell on Linux OS only. Now, blank what to do. I don't like to change my OS to be linux permanently.

You can install Cygwin

Thank you, i will try.

install virtual box for win 7

You could install cygwin or VMware