Version 1.9 of the driver pack is known for its wide-ranging support across various Xperia board and chipset configurations:
During installation, Windows will pop up red warning boxes saying the publisher is unverified. Click for every prompt to ensure a successful setup. Why You Need This Tool flashtool xperia driver pack v1.9
FlashTool Xperia Driver Pack is a collection of drivers that allows you to flash firmware on Sony Xperia devices using the FlashTool software. Here's what I found: Version 1