Changing the number of processors in the msconfig utility can sometimes cause issues if it is not done correctly. The most common problem is that the system may not boot properly, which seems to be the case with your laptop.
Here are a few things you can try to resolve the issue:
1. Restart your computer and press the F8 key to access the advanced startup options. From there, select the "Last Known Good Configuration" option and press Enter. This will revert your system configuration to the last known working state.
2. If the above step doesn't work, try booting your laptop in safe mode. To do this, restart your computer and press the F8 key to access the advanced startup options. From there, select the "Safe Mode" option and press Enter. Once you are in safe mode, open the msconfig utility and change the number of processors back to its original value.
3. If none of these steps work, you may need to use a system restore point to revert your system configuration to a previous state. To do this, restart your computer and press the F8 key to access the advanced startup options. From there, select the "Repair Your Computer" option and follow the prompts to restore your system.
In the future, it's important to be careful when making changes to your system configuration, especially when it comes to processor settings. If you're not sure what you're doing, it's best to consult with a professional or simply not make any changes at all.