Today in the morning when I tried to access my one of the website it displayed titled error. I got socked that why this error coming up. The reason was my Database Host Provider where changed the server and he missed something to activate for my database and this causes the error "Database 'compuzitdb1' cannot be opened due to inaccessible files or insufficient memory or disk space".
When I contacted to DB experts they told me to be relax because it is a normal DB error and can be fixed by trying the following checks.
1) If possible add more hard drive space either by removing of unnecessary files from hard drive or add new hard drive with larger size.
2) Check if the database is set to Autogrow on.
3) Check if the account which is trying to access the database has enough permission to perform operation.
4) Make sure that .mdf and .ldf file are not marked as read only on operating system file system level.
I hope this post will help you to fix such issues. Comment please.