The Dell XPS 410 does not support overclocking in the BIOS.
To get into the BIOS setup, follow these steps. Documentation
1. Turn on (or restart) your computer.
2. When the blue DELL™ logo is displayed, watch for the F2 prompt to appear.
3. Once the F2 prompt appears, press <F2> immediately.
NOTE: The F2 prompt indicates that the keyboard has initialized. If you press <F2> before you are prompted, the keystroke will be lost.
4. If you wait too long and the operating system logo appears, continue to wait until you see the Microsoft® Windows® desktop, then shut down your computer (see Turning Off Your Computer) and try again.
If you open it up and get the Mfg. and model of the motherboard you may be able to find some information searching for dell + motherboard model in search.