Email and internet access has been wiped out for more than a month at one of the state's biggest high schools, disrupting teacher preparation and the start of the school year for students. Staff and pupils at Glenunga International High school have been off-line since the end of December because of "unbelievably slow" repair work.
Principal Bob Knight said a school error in updating staff records caused the problem.
"All of our teachers were deleted from both their emails and from the internet - that happened at the end of December - and we're only just getting everybody back online," Mr Knight said.
Painstaking work to restore the email and access accounts has taken up to three hours for each user, limiting school communications for "virtually all of January" and the first two weeks of term.
"We're just tidying up the last dregs of it now," Mr Knight said.
Teacher preparation and the work of International Baccalaureate students, who start the school year earlier, had suffered, he said.
A spokeswoman for the Education Department said the problem was not the fault of the EduConnect computer system, through which slow internet access had disrupted exam preparation last year, as reported in The Advertiser.
"The significant restoration time was also not related to EduConnect, but due to the large amount of work needed to restore more than 110 staff accounts and check more than 1000 student accounts," she said.
"This included checking associated data including all past and present emails and ensuring the integrity of the data restored."
Opposition education spokesman Duncan McFetridge said there were "problems all over the place" for schools accessing technology. "The whole server needs to be reviewed," he said.
Computers in Education Group of South Australia's Trudy Sweeney, president of the information technology teachers network, said the system was out of date.