Ergh. Just did an OCD
thing with my mouse, and it made me realise just how much OCD wraps itself around my computing activities, as it has done for as long as I can remember. Here's some typical examples of what I experience on a computer:
1. I'll click the mouse harder and firmer than usual, sometimes several times; I don't do this all the time, only when OCD/anxiety kicks in more than normal. I've gone through so many mice because of this, over the years. Something about the "clicking" sensation,
has to feel "right", else it bugs me to
no f**king end!"

I'm not as bad with this as I used to be, but that might have something to do with the fact that I use headphones a lot; I think a lot of it is the "sound", but also if I don't
feel that "click", all smooth and .. clicky .. then it
bugs me.
2. Much like the above point, I will press a keyboard key harder and firmer than usual, especially if I feel the click wasn't "right", and I have also gone through several keyboards, over the years. It takes a lot of restraint, sometimes, to
not hit a key much harder than usual. I particularly struggle with the space bar, and the return key. I also sometimes get very obsessed about the sound the keyboard and mouse make.
3. I don't do this anymore, I think, but I used to somewhat religiously organise my operating system, so that the desktop, start-menu, and settings, and God knows what else, were all set perfectly, in the "right" order. Thankfully, this isn't too much of a problem, now, and I simply keep things moderately organised, as apposed to incessantly perfect.
4. I often obsessively re-read what I submit on forums, Facebook, IMs, and more.
5. I'll sometimes
save rather a lot, while, say, typing out a text document, but this is a grey area, as, with how computers can be, it's always good to save now and again!
6. FPS in games (frames per second) get me really obsessive, and is partly the reason I spent
well over a grand (GBP) on my PC. I cannot effing stand invariable frame rates, to the point of
not playing the game at all. I can't tell you how many times I have spent money on a game, only to not play it, because the FPS bugs the crap out of me. Sometimes I can stomach it, but most of the time, I just cannot let it go.
7. When it comes to fixing, upgrading, or building a computer, I get very obsessive about what I do, whether I'll make a mistake, and so on; this really does get on my nerves, when I'm busy with my head in a computer. ¬_¬
8. I used to religiously defragment my HDDs (basically, I 'tidied' up the storage space, on the PC) but thankfully, ever since Windows 7, I haven't needed to, as it seems to just do it all itself, and is great at managing file locations. I remember back in the day, I used to just run a defrag' every couple of days, and I even recall sitting in-front of my PC, just watching the process take place, even though it used to take up to hours. Granted, I doubt I sat there for the entire process, but I certainly watched a fair bit! (I was fascinated by it, but I think there was an OCD thing to it)
Can't think of anything else, off-hand - how about you guys?