When I install other module,
the left block such as "register now" in the menu bar which is point to the wrong page , which is point to
"URL/modules/subscription/index.php" which is wrong,
it seem to be "URL/register.php" ,
how to fix it ?

if you are using XOOPS 2.0.13.2 or so.
to change the XOOPS login block:

*if you are using a custom template. edit: system -- system_block_login.html and change the register link.

*if you are using the default template and the link is not the right link. i would suggest reuploading the template file. or editing and uploading (system_block_login.html) and turn on "Update module template .html files from themes/your theme/templates directory?" to YES. and then check you login block. to see if the changes took effect and then . change "Update module template .html files from themes/your theme/templates directory?" to NO

this is also the same process for uploading/editing any template file(s)