In one of the UK's largest XP implementations, HBOS Group, which includes Halifax Bank of Scotland, Intelligent Finance, Birmingham Midshires and Clerical Medical, aims to install Windows XP on 70,000 desktops and 5,000 laptops.
The XP project began last year and is part of a bigger programme to create a common banking platform, estimated to be costing more than £100m.
In an internal e-mail to HBOS staff dated 17 March, Martin Ewart, head of group technology at HBOS, said, "The key issue is the robustness of the tools used to upgrade the softwareÉ We have a serious technical issue with our software deployment. This includes IBM's Tivoli product, which is being addressed at the highest level in Global IBM."
Tivoli is used to manage PC infrastructure and deploy software.
The internal e-mail continued, "We are supporting the 850 PCs we have already implemented using manual updates, but these are not appropriate for large-scale, customer-facing business operations."
An HBOS spokesman said it was good project management to temporarily halt the project. "Until we resolve the issues it would not be wise to put XP on another 10,000 desktops," he said.
"We are looking at the IBM Tivoli [product], but it is not just the fault of the software. We are pulling together lots of different software products that were not designed to work together."
IBM declined to comment.