Hi Sarah
If the will was probated through the courts then, yes, it would be registered.
It costs £5 to order a copy by post see
http://www.hmcourts-service.gov.uk/cms/1226.htmThe actual indexes are free to view at First Avenue House, High Holborn, London and will give name, date & place of death, value & executor. However, it costs £5 to see the will whether you apply in person at First Avenue House or by post as above.
This applies for post 1858 wills and be sure to ask for a copy of both the will and grant of representation if you apply.
Of course, this is all assuming that it would be a will probated through the courts and not some kind of do-it-yourself will that was sorted directly by family or friends

Hope this helps
Casalguidi