Security has been increased at the campus in the Afghan capital after the attack last August, in which students trapped during the nearly 10-hour raid sent anguished pleas for help on social media.
"I don't think anything un-Islamic or against any group is taught here," said Rahmatullah, a returning student who was one of those wounded in the attack.
"It is just a centre to promote knowledge and that is going to succeed," he said.
The university, which opened in 2006 and has more than 1,700 students, was long seen as a high-profile target for militants, partly because it attracts foreign faculty members.
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The attack has cast a pall over the education sector, seen as a rare symbol of hope for the young at a time of rising insecurity.
"All our classes will resume today. We have worked on boosting the security of the university for the past seven months," Zubaida Akbar, the university's director of communication, told AFP.
Private security companies were banned from operating independently in Afghanistan in 2010 in an attempt to control illegal weapons in the war-torn country, and must register with the government.
The raid began with a suicide bombing at the campus gates which paved the way for two gunmen to enter to compound at dusk, when it is usually packed with students.
No group claimed responsibility, but it occurred during a Taliban summer offensive against the Western-backed government.
Their whereabouts are still unknown and no group so far has publicly claimed responsibility for the abductions, the latest in a series of kidnappings of foreigners.