Philip has indeed covered it although he left one bit for me to find (consolation prize

His battalion was 2nd Battalion G Gds who fought initially in 4th Guards Brigade in 2nd Division until August 1915 when they transferred to 1st Guards Brigade in the Guards Division. Given the date he went to France, he was already serving as a regular soldier when war broke out.
However he was taken prisoner in the very early stages of the war. He appears on a Red Cross lists dated November 1914 as being in the POW camp at Doberitz:
https://grandeguerre.icrc.org/en/List/3071057/698/301/ There are no other Red Cross records for him.
His service record seems to have been among those that were lost in WW2 to bombing and one has to assume that he remained in that camp or others until the end of the war.
If you have another £3.50 to spare, you could download the war diary of his battalion here:
https://discovery.nationalarchives.gov.uk/details/r/C7351962 It has to be remembered that the period covered in August to November is what became known as the retreat from Mons so the diary may be short on detail.
MaxD
** I am investigating another avenue for his record.