Hello,I have an acer (aspire 5536g), just turn it on and found a message
Broadcom UNDI PXE-2.1 v11.4.1
Copyright (c) 2000-2008 broadcom Corporation
Copyright (c) 1997-2000 Intel Corporation
All rights reserved.

Broadcom Base Code PXE-2.1v1.1.0
Copyright (c) 2000-2008 broadcom Corporation
Copyright (c) 1997-2000 Intel Corporation
PXE-E61: Media test failure, check cable
PXE-MOF: Exiting Broaadcom PXE ROM
Operating System not found

I really need help, I don't not much about computers, but all my homework and lectures are in it... Please help

Either,
A) Your computer has been configured in the BIOS to network boot only and it isn't finding a boot server, or...

B) The hard drive has failed or been removed from the BIOS boot order.

Any chance your buddies are messing with you by changing your BIOS configuration?