It doesn't really matter if you are a student or a seasoned professional it is important to make sure your cover letter is specific to each job you are applying. While it may be easier to use the same cover page for every employer it will deaden your opportunities and lower your chances of getting called for an interview.
A cover letter is a statement about who you are and why you match the position. Because this is the first thing the hiring manager sees it is important to be very specific about why you match the position.
If the listing is asking for computer skills and Microsoft Office experience then apparently it is very important to them. You will want to state how you have those skills in the very first paragraph.
There may also be some generic skills that are common to positions of your industry. These are fine to state in a second paragraph and applied to all cover letters in that industry.
Try and keep your cover page as short as possible. One should be able to get 70% of the information in 10 seconds so they can put you in the "follow up" pile.
You will still want to use a professional business letter format. It is these small impressions that can make a big difference.