I need help finding the problem with my cam

Hello,

Kaii so , i bought a new webcam yesterday ,
&& it was working just fine last night , but this morning
it stopped, so i bought a new one, & it gave me the sme problem
so unplugged it , & then put it back in
& when i tried to go on web cam with some people,
it would automatically cancel the invatation , when i would accept
& the same when they would accept.