I will be building a computer in the next few weeks and I want an ssd that JUST has windows on it. I will have Windows 7 Home Premium 64-bit. I'm looking at the OCZ Vertex 4 64gb....I'm wondering if that will be big enough. Thank you.
A 64GB SSD should be sufficient. Keep in mind that you need enough space for Windows, and then a couple odd DLLs for every other program you install, since Windows requires certain DLLs be in the Windows directory.
I think Windows 7 needs roughly 20GB, though I could easily be well off, but that would still leave you with approx 40GB for the other misc things, which should be quite sufficient.
64gb will do if it's going to stay nothing but a boot drive but my guess is you'll wish you could put more on it as you go. I wouldn't go less than 120GB because you'll have a few things you're going to wish you could put on there. Plus, 120/128 gb drives are on sale pretty cheap now. The Samsung 840 (non-pro) was only $100 recently and you can find others cheaper. my 2 cents anyway.