There is still available an unlimited lifetime, freeware version of Mestrec (version 2.3), but isn't as pretty as the latest versions and only does 1D spectra - the most usual types of 1H, 13C, 19F, 31P etc etc ...
Do a Google (or equivalent search) - I found
http://sif.iisc.ernet.in/mes.htm straight away.
Other free alternatives that I am aware of are:
SpinWorks from the University of Manitoba
http://www.umanitoba.ca/chemistry/nmr/spinworks/and Joel's freeware (but you need to register it with them to unlock it) program Delta.
Of these MestreC is my favourite - and the one I use all the time.
You could also look around the University of Oxford's NMR pages - they link all sorts of NMR items:
http://www.chem.ox.ac.uk/spectroscopy/nmr/websites.htmHope this helps!