kinematics

Hello guys, I really need help and the problems listed above seems quite similar. I am using version 5.0 and everything has been working just fine for quite awhile now. The system still boots up but if I were to copy or write any information into the NAS, it would suddenly just hang in the midst of the transfer process till a hard reset. I've taken the computer out and blew out all the dust since is has been with me for quite awhile. I've also checked if the PSU has enough power for the system. The last possibility of this problem was that I was clearing out the NAS afew days ago and I saw some hidden files and figured it was what the apple computers left behind and did a quick select and delete without thinking. Is there anything placed on the hard drives that I could delete that would render a problem like this? Thanks!