That would cost less. A new hard drive would be as little as $50 and a newer version of Windows will be another $100 or so. You're probably better off going with Windows 7 rather than 8 because your computer will almost certainly run 7 but is much less likely to run 8.1. Windows 8.1 has a couple of hardware requirements that cut out a lot of older computers from being able to run it, and if yours runs XP, it's likely it won't work.
I just looked at Newegg's email they sent out a couple of days ago, and if you're really on a budget you could do it all for a little over $100. They have a refurbished 160 GB hard drive for only $20 and Windows 7 for $85. I probably wouldn't go with a refurbished hard drive myself, but it would probably be okay. Just go to Newegg and click on "latest email deals" at the top. At the very least you can save a bit on Windows.
I just looked at Newegg's email they sent out a couple of days ago, and if you're really on a budget you could do it all for a little over $100. They have a refurbished 160 GB hard drive for only $20 and Windows 7 for $85. I probably wouldn't go with a refurbished hard drive myself, but it would probably be okay. Just go to Newegg and click on "latest email deals" at the top. At the very least you can save a bit on Windows.