Could not reserve enough space for object heap

I bought and installed 4gb of ram today for my minecraft server, I write this in the .bat
@echo off
java -Xmx3072m -Xms3072m -jar craftbukkit-0.0.1-SNAPSHOT.jar
pause
and it claims I do not have enough ram...why when theirs 4 available... here's the message it gives me
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
Press any key to continue . . .

I am running windows vista 32 bit.

 

i doubt you have 4G available in a vista 32bit machine

 

and by available, he means accessible... as far as i know, the best you are going to get is around 1.5, and even that is tricky.
try Xmx1G
then try Xmx1536M (EDIT)

however, if this is a standalone server and you have 64bit hardware, your simplest legal option is to dump vista and install linux. Bonus: no crazy firewall tricks

 

You have to use full numbers so 1.5G wont work, u have to use 1536M.

 

thanks