pic16f877 ram problem

I have a problem in pic16f877
the program that I made dosn't work properly.
some ram location work but the other ram location don't work. I used CCS C compiler to program.
my program work good on Proteus correcctly but when I made it on board real time does'nt work properly.
some Ram location seem don't work. because the value that must be in ram location don't seem there.

has anione to know this problem.
by.

In most PIC varieties there are locations which are not implemented. You also need to be quite sure that you know where the register file bank select bit are. Either of these conditions could cause the behavior that you describe.

Are you saying that none of your register file locations are working or are you saying tha the ones you want to use are not working?