KB article Q166839, updated 15-May-1997, contains some usefull information about installing Hotfixes with Service Pack 3, but it is incorrect and incomplete in the "How to" section.
Starting With Windows NT 4.0 Service Pack 3, Update.exe will update your NT 4.0 install to the service pack and will install any specified HOTFIXes. The steps required to accomplish this are:
1. Copy all service pack files to a directory, i.e. C:\SP3. You can expand a Service Pack by typing: ServicePackFileName.exe /x
2. Create a subdirectory under SP3 called HOTFIX
3. Copy hotfix.inf and hotfix.exe to this directory. I have a ZIP file that includes a sample combined hotfix.inf.
You can see from the COMMENT line at the bottom that this custom HOTFIX contains:
Q143478 - oobfix_i
Q168748 - javafixi
Q154087 - lsa-fixi
Q170510 - w32kfixi
Q154174 - icmpfixi
Q146965 - admnsymi
Q154460 - chargeni
4. Copy the actual files that make up the hotfixes into this directory (you may ignore the *.dbg files). You must expand the hotfix exe files in date order, earliest first so that you get the latest version of a duplicate file. Type HotfixFileName.exe /x to expand a hotfix.
5. Open up the sample hotfix.inf file and add the files in the appropriate sections from the expanded hotfix.inf Download my ZIP and compare it with any single HOTFIX and you will see what I mean.
6. Save your INF file and run update.exe. After SP3 files are copied, you will be prompted to verify that you want to have HOTFIXES installed. Choose Yes.
If you are prompted for the location of your Service Pack files, just point to the SP directory, i.e. SP3.
If you uninstall the Service Pack, you will be prompted to remove the HOTFIX.