The Government is launching a ministerial inquiry and technical audit into the Novopay payroll saga.
A contingency plan, which may involve replacing Novopay, will also be investigated, but the Government is sticking with the troubled payroll system for the time being.
Cabinet minister Steven Joyce says a plan to accelerate the solving of software problems and further resources and staff will be put into place to fix the problems, which have seen hundreds of teachers go unpaid and schools go into the red.
He said the extra cost was likely to run to millions of dollars.
The Government will supply cash and resources until contractual issues are worked out with provider Talent2.
The technical audit will be carried out by Deloittes to examine the "stability" of the payroll system.
It will report back on whether problems were "critical", Joyce said.
He said the Ministry of Education would be more involved with schools, document their feedback and provide more training.
Rolling back on Novopay was "not a decision you would take lightly", and he would prefer not to "jump horses".
He said it was one of the largest and most complicated payrolls in Australasia, and there was no quick fix.
It was "too challenging" to say when teachers would begin to be paid correctly, but the remediation plan stretched "to weeks, even months".
He would take a proposal for a ministerial inquiry to the Cabinet and it would take three to four months, but he did not want an inquiry to get in the way of fixing the problems.
Joyce was handed responsibility for fixing Novopay after Education Minister Hekia Parata and former associate minister Craig Foss failed to get to grips with the debacle.
Novopay was rolled out in August and problems began in September.
Should schools be using dogs to detect drugs?Related story: Demand rises for drug dogs at schools