How to block students access?
You have to change a student's status to "Suspended/Access disabled" from "Student Records"
to block student's access.
You can block some features globally from "Setup & Customization" > "Account & Profile" .
From here you can select the check boxes :
a. Don't allow parents and students to view progress reports (under Progress Reports)
b. Don't allow parents and students to view transcript (under Transcripts)
c. Don't allow parents and students to view mid-term reports (under Mid-term reports)
d. Don't allow parents and students to view reportcard (under Report cards)
e. Disable complaints and issues posting by parents and students (under Complaints and Issues)