|Either the boot order settings have changed in the BIOS (network is listed before HDD) or your HDD is no longer being recognized & it's being bypassed. The network is probably the next in line in the boot order.|
To get into the BIOS you need to press the proper key during bootup. There are several possibilities depending on what type of system you have...try DEL, F1 or F2. It may even be displayed on your screen during bootup. For example, it would say, "Press DEL to enter setup...."