Pull the memory, and then put a single stick back in (Slot 0, generally closest to the CPU if not labeled.) Try to boot it up. If you get past the beep codes, you may be fine. If they happen again, try swapping the stick you plugged in with the other you pulled (assuming you have more than one). If unplugging both sticks of RAM doesn't work, start troubleshooting your boot errors by disconnecting everything not needed for POST (Motherboard, CPU, Memory, Keyboard, & Video Card).
The CMOS battery will allow you to remove any BIOS password configured on the machine--but because of how your question is phrased, I just want to clarify that it will not affect the Windows Administrator password in any way.
Leave the CMOS battery disconnected for 20-30 seconds, and ensure the PC is not connected to a power supply while you do this. If your machine is connected to power, wait an additional 20-30 seconds after unplugging from the wall (so any residual charge can dissipate through the various voltage drops on the board). If the battery is soldered, you may look for and jumper the pins on the board that are labeled as having to do with the CMOS and/or Battery in lieu of removing the button cell.