Creaky stairs

[chriselevate]

Bought a 1970's detached house and the stairs are rather creaky. There carpet laid on the stairs and access under the stairs. I've cleared there understairs cupboard and there's a board covering the under side of the stairs. If I pulled if off is there something I could do to quieten the creaking?

Thanks for any help, tips and advice you can give.

 

[big-all]

pictures off the wedges/wooden blocks
and the point the tread and risers join front and back off tread

 

[chriselevate]

Sorry this'll be the first time I've done this so I not sure what you mean here.

 

[big-all]

ok look under the stair
look at the tread [the bit you walk on] take a picture off any added bits off wood each side and inbetween
also where the tread meets the riser [the bit that goes up to the next tread]at the back off the tread