Hi everyone, new to the forum here. A friend of mine built me a PC about 8 months ago. As the tower was getting a little 'warm', I decided to open up the tower and clean the fan using compressed air and also (what I think is the CPU, as it was just behind the fan) a little brush as it was covered in dust (the brush is kind of like the thing old ladies use when dying their hair on the roots, it's like a long black brush and isn't very hard at all, I've read that people have cleaned them using a toothbrush, I'd never do that). Anyway, since then, my PC is alot louder than usual, it tends to make a noise which is like some kind of scraping sound and the 'beep' sound on startup sounds a bit different (hard to explain, but not as clear or healthy sounding, if that makes sense). It seems to be running fine though, no problems at all but I am concerned about the loud noise (like a gentle scraping like sound) and how the beeping sound is different from before. It could just be a noisy fan and now that it's clean it's even noisier (especially when starting up). As I know nothing about computers, I'm somewhat afraid that I've done something drastically wrong when cleaning the inside of my PC fan and the front of my CPU. Or it could have always been that way but I never really noticed it before (I'm very OCD about computers). I should also mention that I didn't touch the hard drive when I cleaned out the components. Should I have reason to be concerned? I'd hate to think that one day my PC would pack up on me as it cost me quite a bit and I do all my work and just about everything on there. Needless to say, it's very precious to me. It may just be a 'cosmetic' thing as everything seems to work just fine, it's just the noise and the weird beep when it starts up. Thanks in advance- Roygbiv.