I am trying to build a conputer rig for my son for Christmas and have run into some snags.  This is my 4th build and have not had any problems with others.  I have a GA-890FX-UD5 with an AMD Phenom II 1090T with a psu of 700w and the graphics card is a HD5450.  I did a new install of Windows 7  64 and now I cannot get into the BIOS menu.  I have tried several keyboards including a ps2.  The CMOS has been cleared several times and I have falshed the BIOS to F6 through @Bios as this is my only option at the moment as I do not have keyboard control during bootup.  After trial and error I have found that I can get into BIOS menu (randomly) by pressing TAB and then DELETE.  Once in there though I cannot navigate too well as keys are limited.  To move around I have to press TAB and then an arror key.  Sometimes it will freeze and I will have to do a reboot.  If I allow the computer to boot into Windows, the keyboard and mouse are fully functional therefore I don't believe it is a keyboard problem.  Device Manager shows no issues with USB ports.  I have read many forums regarding others having similar issues and have tried some solutions without success.
Any one- please help.