does anyone know how to fix error -2100f? if so please reply asap.

Error code -2100F typically indicates an issue with your Mac connecting to the internet during internet recovery mode.This mode relies on internet access to download and reinstall the macOS.

Here are some possible reasons for error -2100F:

• Weak Wi-Fi Signal: If your Wi-Fi signal is weak, your Mac might struggle to connect and download the necessary files.
• Incorrect Wi-Fi Password: Make sure you're entering the correct password for the Wi-Fi network you're trying to connect to.
• Router Issues: There could be a temporary problem with your router that's preventing a stable connection.
• Internal Hardware Issues: In rare cases, the error might point to a hardware problem with your Mac's Wi-Fi component.

Here's what you can try to fix the error:

• Stronger Wi-Fi Connection: Move your Mac closer to the Wi-Fi router for a stronger signal.
• Ethernet Cable: If possible, try connecting your Mac to the router using an Ethernet cable for a more reliable connection. This bypasses Wi-Fi altogether.
• Different Wi-Fi Network: Connect to a different Wi-Fi network with a known strong signal and password.
• Apple Support: If none of the above solutions work, it's recommended to contact Apple Support for further assistance. They can help diagnose the issue and provide more specific troubleshooting steps.

In Internet Recovery, these low negative thousands error messages (between -1000 and -7005) indicate that your provided Wi-Fi Network is inadequate in some fashion, and cannot be used (for this purpose) in its current state.

Common problems include:

Hidden Network-name

required use of a proxy server to get Internet access

required use of a login page to get Internet access

Use of a login server or certificate to get Internet access

Use of PPPoE in the Mac to get Internet access (typically only applies to DSL)

Use of Fixed IP address rather than good old DHCP

Variance of the Time by more than five minutes. if your battery has run flat, the time will likely be wonky and have to be specified with a Terminal command

Failure of Router to provide workable DNS server addresses, or providing 0.0.0.0 [may produce -2002f]

If you have an Ethernet port, you may in some cases be able to move your Mac close to the Router and connect to the Router using Ethernet.

The higher the number, the more obscure the problem.