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0X80070645

Network Network-Related Access Denied Applies to: Windows 7, Windows 10, Windows 11

What it means

A permissions issue when accessing a network share or resource — the account doesn't have the rights the target expects, or Windows is specifically blocking a type of access it now treats as insecure by default.

Also seen as: 0x80070645

Quick fix steps

  1. Confirm you're signing into the network share with the correct username and password.
  2. Ask the share's owner/administrator to confirm your account has access.
  3. Try accessing via the IP address instead of the device name to rule out a name resolution issue.
  4. If the message specifically mentions "unauthenticated guest access" or "security policies block," this is a different, well-documented cause: Windows now blocks unauthenticated guest logons by default, which breaks access to older NAS devices, older Windows PCs, and anything else relying on guest-only sharing without a real login. Fixing the share itself to require actual authentication is the properly secure fix; if that's not possible and you understand the tradeoff, you can allow it on the Windows Guidance: Windows+R > gpedit.msc > Computer Configuration > Administrative Templates > Network > Lanman Workstation > "Enable insecure guest logons" > Enabled (on Home editions without gpedit, the equivalent registry value is AllowInsecureGuestAuth under HKLM\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters, set to 1). Be aware this specifically disables security protections against man-in-the-middle attacks on that connection — Microsoft recommends against leaving it enabled long-term.
Still stuck after these steps? Contact us with the exact error text and what you were doing when it appeared.

Frequently Asked Questions

Is enabling insecure guest logons dangerous?
It removes a security protection against man-in-the-middle attacks on that specific connection, so it's a real tradeoff — reasonable temporarily for a trusted home network, but not something to leave on permanently or use on an untrusted network.
Is there a way to fix this without lowering security?
Yes — updating the older device or NAS to support proper authenticated access, if possible, is the more secure long-term fix rather than lowering your PC's security to accommodate it.

Other error codes

0X80072EFD — A Connection with the Server Could Not Be Established

A general connectivity failure reaching a Microsoft service — usually your network, a firewall, or a proxy/VPN blocking the connection.

0X80070424 — A Required Service Cannot Be Started

A Windows service the current task depends on (often related to Windows Update, Security Center, or networking) isn't running.

0X80072EE7 — Store/Update Connection Timed Out

A connection to Microsoft's servers timed out — usually a network stability issue or DNS problem.

DNS-PROBE-FINISHED-NXDOMAIN — DNS_PROBE_FINISHED_NXDOMAIN

The browser couldn't resolve a website's address at all — the DNS lookup found nothing, which usually points to your DNS settings or the site being genuinely down.