One of my friends came to US on H1B. He was in job but these days he is on bench as project on which he was working ended 1.5 months back. Now the situation is that the employer's company has been closed. What is his position at this time. Can he still change the employer and is he eligible to work in US.

It depends on when he was last employed with the company, best to file immediately, and mot make any misrepresentation to the USCIS on the form and ask for the EOS. They will generally approve cases if there is minimal gap in employment. Good luck to your friend.

Hi I am andy, right now I am in h1 and I want to think about to move f1 for study(4 month) so after 4 mon. can I change my f1 to h1 again?

And what is the exact procedure for this?
Thanks