fMy laptop fan :(!

Hey guys, I've got some problem in my Dell Inspiron fan. It was working fine till the day before yesterday but now I don't hear any noise from the fan or feel any air near it. My computer is lagging a lot due to it. Please can u guys suggest me some ways to fix it. And also if u could recommend some software to check my hardwares are working fine or not. -Thanks in advance Regards Areeb