where did you find that fail, it does not look right. to me.

go to F2 USB  page turn on USB boot.

turn on ALL USB ports same place, f2

To flash BIOS , this old PC is well OLD, and has no f12 BIOS UPDATE

The last BIOS is 2000  at del, 2 decades ago , for GX260 only at dell.com ok. nobody else or bad happens.

V13 is it. and is 545.59 KB, not like your illegal huge file exe. a virus no less that. (yours)

SO TO FLASH IT. DO THIS DO NOT SKIP STEPS..

1. NEW RTC COIN CELL NOW.. $1 FIX, DO NOT FLASH FIRMWARE WITH BAD BATTERY !
2. get V13 exe from dell . only.XPSR_A13.EXE  !!!!!!!!!!!!!!!
3. then get dells DDDP DELL DOS FROM DELL>com. seen here.
4. get a $4 stick USB from walmart. in PC section there,  16GB is cheap now.
5. use DDDP to make the stick a boot,USB stick drive...
6. make sure BIOS  is USB boot enabled, My guess you forgot that.
7. move my EXE above (copy) it to DDDP stick
8. boot the stick
9. run the exe , type its name DOS method..
10. it runs and work, , reboot and good to go. when it tells you it is done..

i watched video of A2 bios here and no usb boot seen,, so use CD boot, it does that, use imgburn to do that.

but make it boot to DOS (freedos) and use  the EXE above..

making FREEDOS, boot CD is not simple but well documented.

that Gx260 is really just junk, it has no vallue but it will boot to CD for sure but many 17 year old CD drives are now dead..  and you need CD-R drive burner to burn you exe rom file with DOS BOOT.

nut shell.

get this ISO

https://www.freedos.org/download/

I take that ISO and using any ISO editor add the Dell EXE above to the ISO, (winISO)

then I burn the ISO new to my new CD-r disk  )

then boot the Cd

and then type the the EXE name above using that Freedos booted Cd..

there I answered both ways.

A09

• The Floppy Format is recommended for most users. Floppy format creates a bootable self-extracting disk.

• The Non-packaged Format is intended for advanced users that only require the bootable disk.

The BR file makes a boot floppy.

https://dl.dell.com/bios/BR89214.exe

The non packaged version is here.

https://dl.dell.com/bios/GX260A09.EXE

Hard drive version is here

https://dl.dell.com/bios/R89214.exe

Bios prior to A09 does not support F12 booting.