PostgreSQL Database performance

Dear Team,

Could you please help me, after changing the below parameters in PostgreSQL
configuration file it was not reflecting in OS level and also Database
performance is degrading.

Example: I am using Windows 2008 R2 server .For PostgreSQL I have allocated
24GB RAM out of 32GB.

However after changing the below parameters, In task bar it is showing 2.7GB
Utilization even though my utilization is more.

So kindly suggest us, whether it will impact or not in Open source
PostgreSQL database

max_connections = 100

shared_buffers = 512MB

effective_cache_size = 24GB

work_mem = 110100kB

maintenance_work_mem = 2GB

checkpoint_segments = 64

checkpoint_completion_target = 0.9

wal_buffers = 16MB

default_statistics_target = 100

Thanks & Regards

Pradeep Kanth