Why not go back to XP?
In truth, apart from the fact that it not longer gets updated, there is absolutely nothing wrong with XP.
Also, now that its not the main O/S, most virus writers will be looking for holes in newer O/S's and the chances are, that XP will be solid as a rock for many years to come.
I used XP64 since it first came out, and I never once had a problem with it... Why not, could actually be potentially a very good question... Even though of course you meant it with a grin.
And just for kicks, I put Vista into a VM last night, and I thought sod it, I will actually plonk it onto my main Laptop for a giggle... So, its on there now. Lets see how long it lasts for LOL