My old desktop PC is really old, I think I got it around 2005 or so. It still runs the Windows XP that came with it and so I'm looking at replacing it as I'm not comfortable using XP any more.

This PC sits in my office next to my desk. I'm not sure on the processor but I'm pretty sure it's got 4GB RAM and a 512GB drive that's maybe half full (I'm not home right now to double-check). I mainly use it for web browsing and some light-weight image editing. The web browsing I do is a bit heavy, eg often have 10 tabs open running Javascript-intensive sites like GMail, Google Docs, etc. I like using Opera as my browser but I'm also happy with Firefox and Chrome.

My initial thought was to get a Raspberry Pi 3B+ and try to use that as a replacement. I haven't used Linux all that much but I like the idea of getting away from Windows and all the hassles that comes with running Windows. I've got a Raspberry Pi that I use with Kodi as a multi-media machine hooked up to my TV. After some research I found that while some people do indeed use the Raspberry Pi as a desktop machine the performance isn't that great when it comes to heavy web use (eg if you want to have more than 6 tabs open at a time). It seems the Pi's 1GB RAM is the problem here.

My second thought was to get a NUC as I like the idea of the small format. I'd still run Linux on it. I had a look at NUC pricing on PB Tech, which lead me to my third thought...

My third thought was that PB Tech sell ex-lease machines quite cheaply. Maybe I should buy one of those and get more bang for my buck? Again, still running Linux.

My fourth thought was why not keep my existing PC and just switch from Windows to Linux? This would be the cheapest option, not new hardware required!

So what I'd like to do now is download and make some Live CDs so I can try some distros out and see what works with my old hardware. It'll also help me decide if switching to Linux is workable for me. If it turns out my old hardware isn't up to the job then I'll go back to one of my earlier ideas and buy something new or ex-lease.

What distros should I look at, considering I'm new to Linux but pretty experienced with Windows? I'd like a desktop that looks something like Windows 7 (I'm not all that keen on the Windows 8 and 10 look). Good compatability with older hardware would be handy. A good community that I can turn to if I run into problems.

I know a few big names like Ubuntu and Debian (is Ubuntu meant to be better for beginners, while Debian is more for experts? But I've heard that Debian is more stable).

Also, should I expect running a Live CD to give me slower performance than if I installed to a HDD? I'm guessing the boot time and load time for opening software would be a lot slower, but once the program (eg web browser) is running then should it run at about the same performance as if everything was on a HDD?