My dad and I recently (as in, the other day) got a copy each of Titan Quest Gold (the game Titan Quest plus its expansion, Immortal Throne). My dad's copy installed on his computer fine, easy, no problems. With mine, my computer wouldn't detect the disk (ie disk was in drive but comp claimed it wasn't). So I borrowed my dad's TQ disk and installed it from that, because my comp decided it would pick up that disk. Then it said I had to restart the comp to complete the installation so I did, but then it decided (during drive detection as part of boot-up sequence) it wasn't gonna pick up the disk again, so I swapped back to my copy and hey presto, it detected it. Wtf...
Then I came to install the expansion, and it detected the disk and installed okay. Then, yes, had to reboot comp again, and again it decided it was gonna stop detecting this disk. So I swapped with my dad again and it worked. Until the next time I booted up my comp, the following morning. Come that evening (this was yesterday), I swapped disks with my dad again because I wanted to play the game and it wasn't picking up the disk. Again. After half an hour it suddenly decided there was a disk in the drive, me having rebooted the comp once in between multiple openings and closings of the drive. I didn't actually get round to playing the game, though, because at that point my sister and her friend got home and he (the friend) started asking me about the Spore thingy so I ended up showing him that, then it was after 11pm and I went to bed.
Anyway, today, now, I've been trying for umm...I dunno, half hour or so maybe, to try and get this thing to work. It still won't read the disk. I'm gonna try rebooting in a minute. Just in case. But this isn't the only time it's done this - it wouldn't detect an Icewind Dale disk my dad got a while back, either. That was a DVD-ROM disk. So is TQ. Disks such as Diablo II (and its expansion) and Morrowind, which are CD-ROMs, have never given me a problem. But I just had a look at the box for Oblivion and that's a DVD-ROM too...and has also never refused to load.
I have no idea what's going on with my comp here. It seems to be very intermittantly detecting the disk. You'd think it'd either work always or never. Weird. And incredibly frustrating, 'cause I wanna play this bloody game

Anyway, any ideas?