Moving a contrib module from /modules into the sites/all/modules folder I need to run a simple fix in my Drupal 7 website. The website administrator, not being a Drupal specialist, installed the SMTP module in the root /modules folder, instead of the /sites/all/modules folder. Now I need to upgrade the SMTP module and noticed the mistake. My first impulse was to move the SMTP folder from /modules into /sites/all/modules, and then proceed with the regular upgrade.

My question is: do you think that moving the SMTP folder from root /modules into /sites/all/modules could cause any problems, like data loss or website crash?
It’s OK (in most cases). Drupal 7 will find new destination of module after registry rebuilding. So, just move folders in proper destination and clear all cache.   

It works for moving modules, but not for disabling and uninstalling. Don't remove module folder before complete uninstalling.

Update: I can move module folder even without disabling that module, because I use Drush for immediate cache clearing. In other situations it will be useful to disable module before moving.