The CHM file under WINXP of Lenovo notebook cannot be opened. The solution to the opening method is as follows:

First, make sure that the HH.EXE file in the WINDOWS directory has not been deleted, and then enter the following at the command line Two commands:

REGSVR32 HHCTRL.OCX and REGSVR32 ITSS.DLL will do. Among them, HH.EXE is the file that comes with the system. If lost accidentally, just copy it from another machine. The two files HHCTRL.OCX and ITSS.DLL can also be copied from other machines and copied to c:\\windows\\system\\.