If you cannot access the machine after if has been powered up, it is still possible to get past the BIOS password. The BIOS password is stored in CMOS memory that is maintained while the PC is powered off by a small battery, which is attached to the motherboard. If you remove this battery, all CMOS information (including the BIOS password) will be lost. You will need to re-enter the correct CMOS setup information to use the machine. The machines owner or user will most likely be alarmed when it is discovered that the BIOS password has been deleted.
On some motherboards, the battery is soldered to the motherboard, making it difficult to remove. If this is the case, you have another alternative. Somewhere on the motherboard you should find a jumper that will clear the BIOS password. If you have the motherboard documentation, you will know where that jumper is. If not, the jumper may be labeled on the motherboard. If you are not fortunate enough for either of these to be the case, you may be able to guess which jumper is the correct jumper. This jumper is usually standing alone near the battery. If you cannot locate this jumper, you might short both of the points where the battery connects to the motherboard.
If all else fails, you may have to clear the BIOS password by resetting the RTC (Real Time Clock) IC (Integrated Circuit) on your motherboard.
The BIOS password may be cleared from a Dell Optiplex by removing the password jumper (PSWD) from the motherboard.
The location of the password jumper on a Dell Optiplex motherboard can be found by reviewing the Optiplex User Guides.
For most Dell Optiplex desktops, the steps to reset a BIOS password and clear all CMOS settings are:
- Locate the 3-pin CMOS password reset jumper on the system board.
- Remove the jumper plug from pins 1 and 2.
- Place the jumper plug on pins 2 and 3 and wait approximately 5 seconds.
- Replace the jumper plug on pins 1 and 2.
Each Dell Inspiron has a master password which will clear the BIOS password. You can get this number by calling Dell Technical Support at (800)624-9896.
Dell Technical Support will request the Service Tag and Express Service Code from the bottom of your Inspiron.
Your Support Tech.