Can not open the bios on a emachine t series

Can't say for sure, but haven't seen a BIOS yet that didn't respond to one of these keys:
Del
Ins
Esc
F1
F2
Backspace

Need to try them several times while the system is checking memory and displaying white on black text. If Windows starts, it's too late.

You can press all of these one after another, several times each, won't harm anything. Of course, it's best to try one, many times, so you know afterwards what worked!