If you have downloaded the XP Service Pack (SP1) from the Microsoft Web Site or even received a SP1 CD, upon attempting to install the service pack you may receive a SetUp Cancelled error message either before the acceptance of the license agreement or just before install.
The problem is usually associated with the files Licdll.dll and Regwizc.dll not being registered on your system. To correct this problem proceed as follows:
1/ Click the Start Button.
2/ From the Start menu select Run.
3/ In the Run dialog box type: regsvr32.exe licdll.dll
4/ Click OK.
5/ The following message should now appear: DllRegisterServer in licdll.dll succeeded.
6/ Click OK to exit the message.
7/ Next click the Start button again.
8/ Now click Run.
9/ In the Run dialog box type: regsvr32.exe regwizc.dll
10/ Click OK.
11/ The following message should now appear: DllRegisterServer in regwizc.dll succeeded.
12/ Click OK to exit the message.
13/ Now restart the Service Pack installation.