New PostgreSQL 9.1 configuration doesn’t work I changed the length of table names in PostgreSQL in the file pg_config_manual.h (in C:\Program Files\PostgreSQL\9.1\include) to 128. Then I reloaded the new configuration by selecting menu "Reload Configuration" under the menu PostgreSQL 9.1 in start menu. Also, I restarted the PostgreSQL. But the change did not take effect. Length of table names in my database still has the limit 64 characters.

How to solve this problem? I am using PostgreSQL 9.1 on Windows 7 Professional.
pg_config_manual.h is not a configuration file, it's part of the source code. After a change in the source code, you have to compile all the code and install the program you just compiled.

Changing the max length for names is not trivial.