I would usually have my pc on all day and fully shut it down at night time before I went to bed. I decided to put it into sleep mode instead the other day and everything was fine but when I woke it from sleep, I was presented with the blue screen of death and it started with some weird noise that sounded like some spinning part was off balance or possibly hitting something periodically. Sounds like it could be a fan or maybe the HDD. I'm not sure why sleep mode would mess up the hardware.
Anyway, now sometimes, randomly, when I turn my computer on from a previous shut down, I still get to hear the noise but the start-up is normal. Sometimes I don't hear anything for the entire duration while I have it on and sometimes it goes away after a few minutes and sometimes it doesn't and I have to restart, like it isn't going away right now. I can hear the noise as I type this. Anyone got possible solutions? I don't want to open the system and mess up other stuff. I'm also not sure if I should take it somewhere to have it fixed - it might not make the noise then and work like normal and nothing would seem like needing to be fixed.
Add: I'm running Windows 7, if that's of any relevance.