The first thing I did was run the Windows 8 Upgrade Assistant. This told me my platform was not compatible. Seriously? I did a little research and discovered many people got that response. It seems like something called NX in the Bios needed to be enabled. Going into the Bios I could not find NX. Since the Bios was an old version I upgraded it hoping the newer version would have a filed for NX. No such luck! Now what?
I tried the Windows 7 Upgrade Advisor. The indication with that was I could upgrade to Windows 7 but only 32-bit. I knew this had to be wrong since my processor was capable of 64 bits.
After more research I found out there is a utility that can be downloaded to check your computer for capabilities. Besides NX (no execute bit) needing to be enabled it also needs SSE2 and PAE (Physical Address Extension) turned on. By the way NX can also be in your Bios as EDB (Execute Disabled Bit), Execute Disabled Memory Protection, EVP (Enhanced Virus Protection), or No Execute Memory Protect. Anyway, by running coreinfo.exe I was able to confirm that everything I needed to upgrade to Windows 8 64-bit was present. For information and a download link click here coreinfo.
At this point everything went smoothly. I suggest you buy the media. Do not download. If downloading to a 32-bit computer you will only get a 32-bit version. In order to upgrade to a 64-bit it is necessary to download to another computer that is 64-bit already. Besides, it is always good to have the install discs in case disaster strikes down the road. Back up all your files since a fresh install is required. Once Windows 8 was installed it was simple to upgrade that to Windows 8.1. That upgrade is free.
Here are a few more links that may be helpful:
I hope this has been a help to you. Feel free to ask questions or leave a comment.