Emachine

Can you help me with my friend's emachine t2895? i cant enter BIOS, how do u? i tried all the f keys, tab, del, ins, shift, nothing each time. i tried closing the comp and opening again but nothing.
It seems clear now that the real problem is that the cpu is unable to read the keyboard after the computer starts. We know it is in working condition because if we press a directional arrow key, the computer will go from off to on. However, the original boot device should have been set to hard drive, but it somehow has managed to go to DVD drive as boot 1, CD-RW drive as boot 2, Floppy A as boot 3, and either no boot 4 or hard drive as boot 4. I tried an XP cd in both cd drives, the CPU could not boot up. Then i tried an older win 98 bootup disk. This you could call "successful", the CPU read it and was able to give the options: 1. boot from hard drive, 2. Boot from cd-rom. From here i knew the keyboard was not being detected, because i was unable to try and select either one. As far as another keyboard, i tried an HP one i know to be in working condition (ps/2) and a wireless usb one, which is also in working condition. Neither of them could be detected, and i could not select "boot from hard drive" or even "boot from cd-rom". For the same reason, it is impossible to enter BIOS because the keyboard and mouse are not detected. I have even tried switching the two PS/2 plugs (mouse w/ keyboard and vise versa), as instructed by someone else. This has not helped. If i am able to make the keyboard and mouse detected in any way, i will be able to enter BIOS and fix the problem. Please help me in figuring out this problem.