I don't understand the question. I boot Windows 98 SE lite from ramdrive. It happens like this. Autoexec.bat creates on image in ramdrive (X from zip file on flashdrive and puts the boot image there. My autoexec.bat takes care of this:
c:\winboot\smartdrv.exe a- b- c- d+
c:\command\xmsdsk 50000 X: /y /t /c2
c:\command\pkunzip c:\windows.zip X: -d -o
mode con codepage prepare=((850) X:\WINDOWS\COMMAND\ega.cpi)
mode con codepage select=850
xmsdsk creates the ramdrive, comspec says where the windows image is. The image registry has been modified with coa2 to think everything lives on x:
By ramdrive do you mean a flash drive, because ramdrives lose their contents when you switch off the machine (unless you have battery backup).