Install older version of BIOS -- How?

I want to use this old laptop for some automotive diagnostic software that requires a native XP environment.  It would not charge the two batteries I had nor the new one I purchased -- just showed that it was charging but the charge percent never increased.

I replaced the motherboard, the charging board, the video card and the AC adapter/charger -- still won't charge.  Everything else seems to be perfect.

I ran across a series of posts on the same issue that said that the problem could be fixed by going back to BIOS A09.  I've tried the hard disk version of the BIOS update and it says I can't because the version I have installed (A11) is newer.    I tried a version that I pulled down fom the Dell FTP site and it opens up a DOS box and then quits, saying that it can't run in a protected environment.  Then I tried the floppy version and it boots and says it updated but when it continues on into BIOS it still shows A11.

Is there a way to install BIOS A09 on a machine that already has A11 installed?  If so, how?

Thanks in advance for your help.