My pendrive is not showing in disk mgmt also what should do ?

Hello,
once what happened that while copying some data i removed and later inserted it but not shown. i got solution of going compmgmt.msc in run and then disk management then change drive letter and path. but option of changing doesnt came up . a remove or... something like that came so i did. i am a boy of 7th standard ... not soo good in computer handling please help me..and yes my pendrive shows, at ejection option right side bottom corner..