Microsoft has halted distribution of its Windows 7 USB/DVD Download tool after questions were raised last week as to whether the software utility makes improper use of open-source code. The tool is designed to help owners of Windows XP-based Netbooks get Windows 7 onto their machines. Microsoft confirmed it has launched a review of matter and taken the utility off its online Microsoft Store until that inquiry has been completed. "Microsoft is looking into this issue and is taking down the (Windows 7 updating) tool from the Microsoft Store site until its review is complete," the company said in a statement. "We apologize to our customers for any inconvenience.".