Not Able to Increase InnoDB Buffer Pool Size in Mysql

I am facing a very rare problem with my DB. I have Windows Server with 64 GB RAM but I am not able to increase innodb buffer pool size in mysql. Current InnoDb buffer pool Size : 1.6G When I increase it and restart Mysql then it throws Error : 161026 0:52:30 [Note] Plugin 'FEDERATED' is disabled. 161026 0:52:31 InnoDB: Initializing buffer pool, size = 2.6G 161026 0:52:31 InnoDB: Error: cannot allocate 2816491520 bytes of InnoDB: memory with malloc! Total allocated memory InnoDB: by InnoDB 22604620 bytes. Operating system errno: 8 InnoDB: Check if you should increase the swap file or InnoDB: ulimits of your operating system. InnoDB: On FreeBSD check you have compiled the OS with InnoDB: a big enough maximum process size. InnoDB: Note that in most 32-bit computers the process InnoDB: memory space is limited to 2 GB or 4 GB. InnoDB: We keep retrying the allocation for 60 seconds... 161026 0:53:31InnoDB: Fatal error: cannot allocate the memory for the buffer pool 161026 0:53:31 [ERROR] Plugin 'InnoDB' init function returned error. 161026 0:53:31 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 161026 0:53:31 [ERROR] Unknown/unsupported table type: INNODB 161026 0:53:31 [ERROR] Aborting I dont have 32 bit OS **but my MYSQL is 32 bit .** I have 64 bit OS on my Windows server. Memory space is limited to 2 GB or 4 GB. For 32 bit Mysql but I am not able to make it 2 GB, my Innodb is only 1.6 GB . Increasing size of Innodb is very necessary because i am getting following error in my error log : MySql.Data.MySqlClient.MySqlException: Can't create a new thread (errno 12); if you are not out of available memory, you can consult the manual for a possible OS-dependent bug What I have Already Tried : 1. I confirmed that My my.ini has no issue . 2. I restrted My mysql many times but innodb size not increasing. At last I got from somewhere that Memory allocation to Mysql in my OS is very less thats why OS is not increasing its innodb size. 3. **I increased virtual memory of windows. It was 8GB before and I increased to to 16 GB. ( Did this change just now and dont know its result because it requires server restart and before 7 hours I cant restart my Server) - Do you think this can solve my problem ?** MySQL Version : 5.1 If anyone know the solution then let me know, i will be very thank ful to you.