mai

I am not sure if it is the right place to post. Feel free to delete / move the post if needed. As you know SchTasks.exe is a command line utility that manage jobs in Task Scheduler. However it is for XP, 2003 and above only. There are info on the net that shows how to hack *XP* version of SchTasks.exe to run on 2000. However, I want to hack *2003* version because it is more versatile. After extensive search I got nothing, so I had to do it myself. My approach is as follow. I opened the executable with PE Explorer and got output from the disassembler. Since the executable was (obviously) doing a check on OS version, it must have called an API such as GetOSVersion(). The API turned out to be VerifyVersionInfo(). According to the MSDN, the 1st argument to this function is a pointer to a version structure. I looked at the disassembler output and located the address of the structure. I spotted a "1" and a "5" there, and my instinct told me that the "1" was the OS minor version and "5" was the OS major version. So I suspected this was why the executable did not work on Windows 2000. So I changed the OS minor version to "0" with a hex editor, and fixed the PE checksum. Then, I copied the hacked binary to a Windows 2000 system and tested it. It seemed have no problems adding and deleting tasks so my problem appeared to have been solved. ------ If you need to run Windows 2003 version of schtasks.exe on Windows 2000, use this procedure Create a copy of SchTasks.exe, say Sch.exe. Open Sch.exe with a hex editor. Search for the pattern 05 00 00 00 01 00 00 00. Change the 01 to 00 (which becomes checking for Windows 2000 or above, rather than XP or above). Save and close the hacked binary. Fix the PE checksum using any available utilities. Google for pechksum, setcsum, etc. BTW, my solution was tested with Windows Server 2003 SP2 version of SchTasks.exe on Windows 2000 Server SP4.