One solution on CHM issue.

if your CHM files could not be opened when your system is XP+SP2, please try the following way,

create one TXT file, and copy the below script into it,

REGEDIT4 [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp] [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions] "MaxAllowedZone"=dword:00000003

save it as *.REG file and run it. then you can read your chm file freely.

Try it.