http://www.pcmag.com/article2/0,2817,2456131,00.asp

"At its recent Build conference, Microsoft lowered the system requirements for Windows 8.1 so more machines can upgrade to the latest OS. The requirements for Windows 7 and Windows 8.1 are now:

• Processor: 1 gigahertz (GHz) or faster
• RAM: 1 gigabyte (GB) (32-bit) or 2GB (64-bit)
• Free hard drive space: 16GB (32-bit) or 20GB (64-bit)
• Graphics card: Microsoft DirectX 9 graphics device with WDDM driver

If you don't have this and you want to upgrade, then it's time for a new laptop or desktop. But if you want to give upgrades a shot, here's how to proceed."

 

Personal opinion, this isn't going to be a pleasant machine to use, it will always be slow.  Many manufacturers sent out PC's with 256mb or 512mb of memory and a few with only 128mb of memory when XP was first released.  As XP gained service packs and people put on programs these computers slowed to a crawl.  In some cases the processor was also pretty slow but I've added memory to a lot of older computers and the people have been very happy.