bios help needed

Greetings all......I previously posted here but didn't really have much luck but the situation's moved on a bit and now I'm here to see if you can move me on a bit further in this prob..........recap..I got hold of a Digital venturis FP575 which only had a 640mb drive...I tried a bigger drive but it wouldn't work...then decided to flash the bios in an attempt to recognise the bigger drive (4.3gig)....flashed with the WRONG bios!!.....then used a crd to get the bios back and I think it actually worked BUT no display!!..blank!!.....so I couldn't even attempt a reflash with the right bios!!...and someone here very wisely suggested that I try an ISA display card....it worked!!....I went back to the link.. http://www.compaq.com/legacysupport/digital/epid43.html and downloaded the 000000o9.exe file and flashed with this and it seemed to work but the display never came back.....having looked closer at the list I noticed that there was a bios with the VGA bios (BG92200a.exe) but I could not understand how to install this bios as it had a different procedure....can someone tell me how to do this as the instructions are a little vague..and if flashing with an older bios is wise??.

"In order to complete the second part of the unpacking, please perform
the following steps:
1) Place a formatted 1.44 Meg 3 1/2" floppy disk in drive A:
2) Type:
DOSIMAGE restore temp.img a:

The DOSIMAGE utility will delete the previous contents of the diskette
and write the new software onto the diskette. DOSIMAGE makes complete
copies of diskettes including boot-tracks, hidden files, and system
files. "

What does step 2 mean exactly and how do I carry this out??
Incidently I tried the larger hd and still get "system disk error" can this even support a larger HD from the one already there??......thanks guys....regards..Dave..