wireless boosters

[#1]

after a marathon +3 months of phone calls, bt engineer visits and major, major frustrations, I have now a stable broadband service but only in one room
I work from home and the wireless service is not behaving in that room nor any room bar the one - it was before all the 'fun and games' of the past 3 months.  I have tried all 13 available channels with no success
just been told to install a booster BUT I already have one
anyone got any advise?  if I change a channel, do I need to change anything on the booster - am not technical so np idea how I would do this even if it would be required!
help....
Phyl

[#2]

it would help if you could advise which router and booster you have and also describe the construction of the walls in the house

[#3]

hi Jim
I have a Solwise 500MBPs device
I am in an approx. 150 year old stone building - walls v thick!
REALLY appreciate your response a its the first time I have used the community so great to get help
Phylippa

[#4]

That seems to be a Home Plug rather than a signal booster
Is this correct
If so you need to consider what you actually need to connect to the internet and where in the property
Do you actually need wireless or would ethernet from the home plug work system