Not really. Once you max out the memory your options become much more limited. You can usually replace your HDD with a faster, larger capacity model. If you are really brave, you can take it apart and add a faster CPU, but these systems are more like laptops than desktops and there isn't a lot you can do to expand them.
What model do you have and what do you have in mind?
From what I saw on-line, you can't upgrade the graphics card. In the BIOS, I am sure you have memory allocation settings (I assume that is what you are asking about). If so, anything more than 512MB (if supported would be a waste). In fact, 256 is probably good assuming you have 2 to 4 GB of main memory.