Okay, so I booted up linux after just being in XP and now, suddenly, for no apparent reason, it's booted into KDE rather than GNOME. Umm... now, firstly, I much prefer KDE, the only problem is that in Opera (I luuurv Opera so don't say "just use Firefox") all the text is slightly fuzzy, as if the resolution is bad/incorrect, but it's not. Zoom is at 100%. In Firefox text is displayed perfectly, it's just Opera

Oh do I switch between booting in Kde and Gnome? I was downstairs whilst it was booting up so I didn't see what happened, and obviously didn't choose it either.

I'm thinking there's gotta be some reason it changed, but hard to say with the info we have.
If you can mention which distro you're using someone might be able to walk you through the easiest way to change it back though.

I'm using Fedora Core 5. I'd rather not change it back, but I'd like to know how to, incase I want to do it. My only problem with KDE is that Opera doesn't look right. :-/

What do you mean "booting up into?" Are you using auto-login? I
would recommend against that, if only to save you the confusion of
things like this. You may have inadvertently saved a local xinitrc
(look in your home directory for .xinitrc) that goes into KDE instead
of GNOME. If you stop auto-login and use your display manager (sounds
like you'll have a choice of GDM or KDM) you can choose which
desktop.

You may have a few other desktops/window managers lurking there that
you may want to try out.

Joel

By booting up into, I mean, I turn my computer on, does a bunch of stuff, and comes to the login screen (I don't have auto-login enabled). Today, the login screen was different so I was a bit like "wtf?" then after logging in, after the desktop was loading up it was different again. Then I had a message (that went away after about 0.5 seconds) that said I was in KDE.

Howdy There,

Check on your display manager screen (the login screen) for any
identifying marks: does it say GNOME Display Manager? or K Display
Manager? In either one you should have a menu marked "Sessions" ---
in KDM it's hidden under the "Menu" button next to the "Login"
button. You should find a Menu that says "Default, Custom, KDE, GNOME, Xfce, Fluxbox,
WindowMaker, Enlightenment (if you're lucky " Use this menu to
choose which session (desktop) you want. They are all there.

Joel