Thieves targeted Knowl Hill Primary School for the second time in a week on Sunday.
A rear door was forced open at the Bath Road school as thieves made their way into an office and attempted to open a safe.
The incident took place between 11.15pm and midnight.
On Saturday last week 10 laptops were stolen from the school after a fence was cut open to gain entry.
A fire door and a cupboard storing the laptops were forced open as they took the hi-tech machines.
The incident took place between 6.30pm on Saturday and 8.30am on Sunday.
Top Ten Articles
The Met Office has issued a yellow alert for Windsor and Maidenhead, Slough and Wokingham, warning that rain moving eastwards across the south of the country may turn to snow in some places.