error invalid boot message

[Michal Connors]

My screen is coming up black with this error and the top of the page when I
try to reboot. I turned off last night and when I restarted this morning I
received the same message.
Here is the exact message:
invalid boot - insert boot diskette in A

 

[richard]

This sounds real bad. Your PC cann't find anny bootable
devices.
The harddisk with windows installed is a boot device.
There can be two things wrong.
1. Your computers BIOS is configured wrongely and won't
load the harddisk with windows anymore at start-up. To
resolve check the manufacter of your main-board for
instruction to check this and (if needed) change it.
2. The windows instalation has an error in the bootsector.
I think the best way to resolve this is to reinstall
windows.