Thanks for all the responses. I used 7-zip 9.20 to extract all files in PRECOPY2.CAB from win98 and then modified file setupx.dll with exescope using these instructions. "In eXescope, expand "Resource" then "String" & find number "96" Click on "96", on the left you will see this number "1526,111" or "1526, 121" or "1526, 115"... ... The last 2 digits may vary depending on the version you have. In any case, change "1526,1xx" into "1526,100" and save. Now, each time you run the install for Win98, you won't have to enter any serial number, nor will there be an upgrade/OEM/full check." Then I used cabpack 1.4a to remake PRECOPY2.CAB. There are still some things I don't understand. Both the modified and original PRECOPY2.CAB use LZX:21 compression yet the modified one now is 2,584KB and the original is 1,305KB. Also when viewing the files inside the modified version using 7-zip, the block column shows all 0's while the original shows mostly 2's and 3's. could someone explain this to me.