I think you're approaching this question slightly wrong.
You're better off looking at which music production program you think is best for you and buying the computer system you need for it.
I can tell you right now that 90% of studio level music is recorded/produced with Pro Tools and the majority of film music composers use Logic Pro these days. Logic requires a Mac, Pro Tools can be either pc or mac (so most studios have both installed on one mac). Pro Tools is VERY expensive, don't buy it unless you actually need it for whatever course you're doing. Logic is cheap but macs are not.
The majority of hobbyists around here will recommend the cheaper alternatives of FL Studio, Reason, Cubase etc. These are pretty much all pc compatible and viable options.
If you're getting them for a music production course (which I assume is true as you said the word semester), ask the course director which program they are going to be using most and get that. In terms of using orchestral samples, you have to buy sample packs anyway and they usually (...usually) work the same on every program (although macs cannot use VST libraries as simply).
If you have a free choice of program just download lots of demos of programs on your existing computer and see what you like.