i may not have followed all of your threads
BUT i would check all the drivers in windows devices manager if you see errors, IE drivers not installed, not working, there was some hints on some *.INF files to install too, some peripherals don't declare themselves, until some INF drivers are installed, because windows does not know them, or what to do with them, until the INF help finding them / or get declared as a peripheral / address ranges etc ...
a windows desktop shortcut can be created with devmgmt.msc
a motherboard change ... I don't recall if Tekscope search for some id's in the bios, only thing i can say, on our 7254
B, i put back an original Intel bios to help restarting it (nvram crash and other things) and it works, and does show more options, but it is some nightmare to reconfigure the lcd screen specs, if the coin cell dies, runs XP fine
on the 7404
non B it is fully original, was restarted too, Radisys SU810 mobo, i don't know on this one .. but as written before : not w2k was working, nor Xp ...
can't play a lot in theses until we buy an Siglent SDS7404A, thoses TEK's are getting very old
Once again, i know you have searched a lot for os recovery disks, i would have said and say again, start from scratch, new build ... do hdd backups ...
install the needed windows from your serial sticker, if it says win 98 win2k xp etc ...
i've lost some of your threads ... and all your history .... sorry
some *.INF files install themselves by clicking on them and right click install .... even putting them in the windows system 32 folder or else etc ... will not activate them, they need to be added in the registry too
posted an inf of the 7104 backup i did, remove the .txt rename it to unsup.inf
the most recent PCI2PCI bridge driver v1.11 dont know for the 1.05 and where you took it ??
there was an cmos utility to validate the LAN port or not, attached here too, i think it was done because there was not enough available IRQ's, if it was enabled, i think you loose an peripheral ?? sorry weak memory at the moment
and i think you had to install some Intel storage drivers too ... not sure
YES THE REPLY #527 .... please when linking something do use the thread number too 
even I get lost in all of this loll see my #943 need to do clean up in my TEK files hdd

for the TI card bus drivers
https://www.driverscape.com/download/texas-instruments-pci-1225-cardbus-controller