Hi

[Dman66]

Good afternoon,im trying to find as much information on my Dads Dad service history,have not found him yet

[Pam Downes]

Hello, and welcome to British-Genealogy.

If you came to us via Forces War Records this will explain the connection.
https://www.british-genealogy.com/th...rs-Please-Read

You don't give any idea of when your grandfather might have been in the Forces, so I'll give both answers.

If he served after 1921 then his records are still held by the Ministry of Defence. See here for details of how to obtain those records.
However if he was in the Navy be aware that prior to 1972 personnel were given their records on leaving so the MoD hold only limited information.
Not sure if you have to be logged-in to FWR to see this.
https://www.forces-war-records.co.uk/tutorials

If you're talking about WWI, then unfortunately nearly 70% of service records were destroyed by fire and bombing. Those that do remain can be viewed on Ancestry and Findmypast. Both are subscription sites, but your local library may have free access to one or both of them. You can also take out a free 14-day trial on both sites but make sure that you untick the 'continuous membership' box or you will find your bank balance has less in it than you thought.

Pam