Theres a problem with my comp I need help...

[Crono]

Okay, sometimes my computer makes this really long beeping noise, it goes "beeeeeeeeeeeeeeeeeeeeep" for like a whole minute straight. This happened last summer too, but it never did it during the winter and spring but now its doin it again...Here are some effects:
On the front of the comp tower there is a red light with a cylinder shape above it, I notice that when my computer beeps this light never does anything, it just stays off until the beeping has stopped, this beeping noise is driving me insane and I dont know whats wrong.......CAN ANYONE HELP ME PLEASE??!!!! I dont know whats wrong!