Why does my computer beep when i type <shift>-DE quickly?

"I suspect that you are triggering three-key rolllover.

IIRC, the keyboard sends the BIOS a key-down and a key-up message for every key you press, including shift, alt and ""windows"" keys. The BIOS converts these into actual characters which are then buffered ready for the program to use.

Some keyboards/laptops and BIOSes will notise if you press a second letter key before releasing the first, or otherwise press multuiple keys in error. Many won't.

There may be a three-key rollover entry in your BIOS settings that you can change.

Failing that, you will have to type slower, and/or turn the volume of your beep down. (I can do that on my HP laptop)."