I have a decent computer that I built years ago. The issues I have, are small ones at that are the following:
1. It is an "older computer". Within the last year I had to replace the motherboard. I actually had to buy a used one on eBay (an identical one to my old one) to replace the old one so nothing had to be modified or changed.
2. I have Windows XP Pro on it. I like XP pro. The issue with XP is that I can not use the current IE and I like using the current IE over the Google Chrome that I am using now. XP is no longer supported by Microsoft (which is not a big deal to me)
To resolve the issues I can do the following:
1. I can install Windows 7 Pro on this system.
2. I can build another computer with Windows 7. Get current or semi-current parts and have a decent and current machine again. I created a build list already but I am not sure that I want to spend money on this right now. This fits into the want category and not the need category right now.
3. Just enjoy the computer that I have right now and use it until I can't no more.
History.
I bought my wife a brand new laptop a couple years ago. I spent the money on it and got what at the time was very current and I did not skimp. My wife enjoys it.
Last year I bought my kids a current computer to replace an older system that I had upgraded over the years and now they have a very good computer. NOW they both have current and fast machines (pity pity me)

What do you think? I know the smart thing is to enjoy the current computer. When it breaks down then build a current machine. I have everything set up on my computer they way I want, programs, different files and such, and its behavior; and why would I want to go through the hassle and start from scratch by installing Windows 7 on this computer or build another...
P.S. I have the free Avast AV program and it seems, just like the Kaspersky I had before on this computer and on my work computer, that the Av programs really bog down the computer at times and that drives me mad. So I do not know if building a new computer will help this AV issue or not.