It's nothing to worry about really, Iv'e come across computer's that have 64mb of memory and had their OS report that there is 63mb of ram in the system. It's not really such a big loss. On paper, it would be like adding another 16mb of ram to a computer that had 32mb of ram, no difference (atleast for a computer that old, but that same principal applies, and in this case there is practically nothnig to worry about or cause concern).
If you have 1024mb of memory in your system, windows will always show it as 1gb in your system properties. Windows reporting how much memory there is in your computer is complete bs anyway, your computer does a better job itself on boot up or in bios showing how much memory is present in your computer.