Hi Lios, the first thing you should do is report to whoever is in charge there that you had a disk failure because this could turn into something terminal! If the hard disk fails again you may loose some or all of your files on the pc.
As for the sound issue we need to know a bit about your pc so go here download the file and post the results.
http://www.gtopala.com/siw-download.html
Dont you have an IT person at your work? or someone who handles probs with the pcs?