Intel® Pentium® Processor G3258
(3M Cache, 3.20 GHz)
Processor Graphics ‡ Intel® HD Graphics
‡ This feature may not be available on all computing systems. Please check with the system vendor to determine if your system delivers this feature, or reference the system specifications (motherboard, processor, chipset, power supply, HDD, graphics controller, memory, BIOS, drivers, virtual machine monitor-VMM, platform software, and/or operating system) for feature compatibility. Functionality, performance, and other benefits of this feature may vary depending on system configuration. http://ark.intel.com/products/82723/Intel-Pentium-Processor-G3258-3M-Cache-3_20-GHz
Im guessing like you originally thought that there is no driver for Vista. It will work with Windows generic drivers, but not as well. As far as updating, I would go with 7 64 bit as I still don't like using 8, too clumsy.