Today is my bad day

For some days my machine (Computer ) does not work properly . So I sat on another machine which is one of MCSE student in our laboratory . But today I was surprised that he has changed his computer password and he has not received my phone call . I am totally angry with this guy . I have never seen such a selfish guy . I have decided not to say him a single word but definitely in future I will get chance to return him with same behavior .