Question : Problem: BIOS problems

I have recently bought a set of parts to build a PC.
I am trying to update my BIOS to use a more recent processor than the board was released with support for. Using an older processor just to get started, I can get into BIOS and change most parameters. I cannot, however, change the System Time or System Date. I can select any of the fields. Instructions are to use + (plus) or - (minus) to change the field values. Does not work. No change is registered using + (plus) or - (minus) on either the num pad or the main keyboard. If I try to enter a value manually e.g 2009, the BIOS Setup locks until I hit ESC and the value in the Time or Date field reverts to default - 00:00:03 on Sat 03/01/1980.
This BIOS (AMI version 08.00.14) gives me options to press DEL to enter Setup or F2 to load default values and continue. I have described the problems with DEL above. If I press F2 instead, I get a blank screen with a single flashing cursor (LHS near the top of the screen). No boot happens either from the HDD which is a full working system disk (Windows XP Home) or from the CD drive with a Windows CD in it. The BIOS successfully detects and identifies the HDD and the CD drive.
So I seem to have two problems - I don't know if they are related:
I can't update the BIOS date and time
I can't get the PC to find an OS to boot into
Anyone seen something like this before? Where do I look?
Faulty mobo, faulty processor or something I can fix?

Equipment specifics
There is some detail on the web about perhaps being able to unlock an AMD X3 processor to become an X4. I am not too bothered about this, but reckoned I may as well if the opportunity is there. Web sense seemed to be that Biostar made good mobos for this, so I bought a Biostar TA790GX 128M.
I also bought an AMD X3 720 processor, 2GB (2 x 1GB) of 800 MHz DDR2 RAM, 480W PSU and have connected the usual FDD, EIDE HDD, CD-RW drive, kbd, mouse, monitor.
First problem was with my X3 processor installed, the machine refused even to get as far as a POST test. Warning lights flashed and after tearing my hair out for a while noticed a small paragraph in small print in the manual saying that 1) the BIOS needed to be updated, 2) the board might not work with AMD2+ processors until the BIOS was updated and 3) therefore I would have to buy or borrow an older AMD2 processor in order to get the BIOS updated. Once I got over the shock of this (I still think it is outrageous), I did buy an older AMD2 processor and have made a little further progress, but not much and not enough to get the BIOS updated.

Answer : Problem: BIOS problems

According to http://www.biostar.com.tw/app/en-us/t-series/introduction.php?S_ID=377, the 5.x versions support X3 and X4 cpus.  Check what revision your board is - it should be written on the side of the motherboard.

I suggest resetting the CMOS, and possibly replacing the CMOS battery as a first step.