ProComp, an industry group backed by some of Microsoft's biggest competitors, has complained to the US Department of Justice that Microsoft has violated terms of a proposed antitrust settlement deal that it reached with the federal government.

ProComp has identified six violations on Microsoft's behalf. Though Microsoft's antitrust deal has not yet come into effect, the company has filed documents with the US courts summarizing how it is already complying with its terms.

The release of Service Pack 1 for Windows XP, a set of product updates and security fixes for the company's operating system was part of this compliance. However, ProComp argues that the 30MB download was not "readily accessible to consumers", and was "non-intuitive" when it came to obtaining it and installing it on a PC.

ProComp members include Oracle and Sun. The group also objected to a feature in the update designed to let end users substitute non-Microsoft applications for some Microsoft ones installed by default on a Windows PC.

The group argues the tool, "Set Program Access and Defaults", is hard to find and complex to use.

The tool's menu allows users to choose, for example, "Windows Media Player" or "my current browser". It doesn't, however, list any other options for competing products such as the Netscape browser. Microsoft wants third-party vendors to tune their software to show up as options in that menu.