Hello, I just download the Hugs 98 Version: Dec 2001 for windows All the hs files are in the C:\Program Files\Hugs98\lib I put your excample Fact.hs in it as well, but I could not load it if I use the "WINHUGS", or "Hugs(Hugs mode)" or "Hugs(Hugs98 mode)" which appears in start->program->Hugs98 the message of it is ///////////////////////////////////////////////////////////////////////// __ __ __ __ ____ ___ _________________________________________ || || || || || || ||__ Hugs 98: Based on the Haskell 98 standard ||___|| ||__|| ||__|| __|| Copyright (c) 1994-2001 ||---|| ___|| World Wide Web: http://haskell.org/hugs || || Report bugs to: hugs-bugs@haskell.org || || Version: December 2001 _________________________________________ Haskell 98 mode: Restart with command line option -98 to enable extensions Reading file "C:\Program Files\Hugs98\\lib\Prelude.hs": Hugs session for: C:\Program Files\Hugs98\\lib\Prelude.hs Type :? for help Prelude> :load Fact.hs Reading file "Fact.hs": ERROR "Fact.hs" - Unable to open file "Fact.hs" Prelude> ////////////////////////////////////////////////////////////////////////// But if I just click the Fact.hs file , it works fine, do you think it is your bug or I did not set up the hugs correctly? yours sincerely Helen _________________________________________________________________ 享用世界上最大的电子邮件系统― MSN Hotmail。 http://www.hotmail.com