LyX installed in Windows XP but cannot start LyX

[Zhiqing Zhang]

Hi, I have just installed a french version of LyX under 
Windows XP. But when I try to start it, I got the following 
error message:

LyX n'a pas pu trouver les descriptions des environnements!
Vérifiez que le fichier <<textclass.lst>> est installé 
correctement.

What should I do in this case?

Many thanks in advance,

Philippe