How to Fix It When the Specified Network Name Is No Longer Available

You’re just trying to open a shared folder, map a drive, run a backup, or copy one innocent little file… and Windows hits you with:
“The specified network name is no longer available.”

Translation: Windows started talking to a network share (usually over SMB file sharing), and then the connection got interrupted, rejected, or yanked away.
It’s the networking equivalent of calling someone and hearing them pick upthen immediately hearing click.

The good news: this error is common, fixable, and usually caused by a handful of repeat offendersSMB version mismatches, name resolution hiccups,
flaky Wi-Fi, device sleep settings, firewall/AV interference, or the server/share dropping off the network.

What the Error Actually Means (In Human Terms)

Windows often reports this as System error 64 (hex 0x40), which maps to
ERROR_NETNAME_DELETED. In plain English: Windows believes the network share name it was using is no longer valid or reachable.

It can show up in a few places:

• File Explorer while opening \ServerShare
• Mapping a drive (GUI or net use)
• Copying large files to a NAS or file server
• Backups and sync tools that write to SMB repositories (CIFS/SMB shares)
• Domain join attempts (yes, even that can trigger it)

Before You Touch Anything: A 60-Second Reality Check

Start with the boring stuff firstbecause boring stuff fixes a surprising amount of “mysterious” network errors.

1) Confirm the share is actually online

• Is the server/NAS powered on?
• Is it connected to the network (Ethernet plugged in, switch lights blinking)?
• Is it asleep or in a low-power mode that cuts off network access?

2) Test basic connectivity

On the Windows PC that’s failing, open Command Prompt and try:

If ping by name fails but ping by IP works, you’re dealing with name resolution (DNS/NetBIOS) more than SMB itself.
If both fail, it’s likely network connectivity.

3) Try the share by IP (quick workaround)

If \ServerNameShare fails, try:

If the IP version works, you’ve just proven the server is reachable and SMB is respondingyour issue is likely DNS, stale cached names,
or how the device is being discovered on the network.

Most Common Causes (And What to Do About Them)

Cause A: SMB version mismatch (the classic)

Many older NAS devices, printers, and legacy file servers still rely on SMBv1. Modern Windows versions increasingly discourage SMBv1
because it’s deprecated and not installed by default in newer releases (starting around Windows 10 version 1709 and equivalent server versions).

When a client and server don’t agree on an SMB version, Windows may connect briefly and then fail with “network name no longer available,” especially during mapping,
browsing, or larger transfers.

What to do (best practice): upgrade the device/server to SMBv2/v3

If you control the NAS or file server, check its settings/firmware and enable SMBv2/SMBv3. This is the safest long-term fix.

What to do (last resort): temporarily enable SMBv1 on Windows

If you’re forced to access a truly old device that only speaks SMBv1, Windows can enable SMB 1.0/CIFS File Sharing Support.
But treat this like eating gas station sushi: possible, sometimes necessary, rarely your best day.
Microsoft documents how SMBv1 can be enabled/disabled and strongly signals it’s deprecated.

Windows Features method:

1. Open Control Panel → Programs → Turn Windows features on or off
2. Find SMB 1.0/CIFS File Sharing Support
3. Enable it (if you absolutely must), reboot, test, and then plan to remove it once you upgrade the device

PowerShell checks (helpful for troubleshooting):

Cause B: Firewall, antivirus, or security software is interrupting SMB

Security tools can block or inspect file-sharing traffic in ways that break mapping or transfersespecially if you’re using a third-party antivirus suite
or you recently changed network profiles (Public vs Private). This is a commonly reported factor in troubleshooting guides.

What to do:

• Confirm your network is set to Private (trusted home/office network).
• Ensure File and Printer Sharing is allowed through Windows Firewall on Private networks.
• If you have third-party AV/firewall software, temporarily disable it just long enough to test (then re-enable it).

If disabling security software “fixes” it, don’t leave protection off. Instead, add proper exceptions for SMB traffic or the specific application doing the transfer.

Cause C: Name resolution problems (DNS and “who are you again?” moments)

Sometimes the server is fine, but your PC is using an outdated IP for the server name, or your router/DNS is confused.
That’s why \IPShare can work while \NameShare fails.

What to do:

Then try again. If your network uses a router as DNS, rebooting the router can also clear stale records (un-glamorous, but effective).

Cause D: The mapped drive or credentials are stale

Windows can cling to old sessions and saved credentials like they’re sentimental scrapbooks.
If the server changed passwords, the share moved, or you toggled between Microsoft accounts, you can end up with authentication failures that surface as weird network errors.

What to do:

1. Open Credential Manager → Windows Credentials and remove entries related to the server/share.
2. Remove old mappings and reconnect cleanly:

Then remap with explicit credentials if needed:

Cause E: Network adapter power saving (your Wi-Fi is “taking a nap”)

If the error happens after your PC sleeps, after inactivity, or mid-transfer, power saving is a prime suspectespecially on laptops.

What to do:

1. Device Manager → Network adapters → (your adapter) → Properties
2. Power Management tab → uncheck “Allow the computer to turn off this device to save power”
3. Also check your NAS/server sleep/spindown settingssome devices “go quiet” and drop SMB sessions.

Step-by-Step Fixes (In the Order That Saves the Most Time)

Step 1: Reboot the right things (not just your feelings)

1. Restart the Windows PC.
2. Restart the file server/NAS if you control it.
3. Reboot the router/switch if multiple devices are affected.

Step 2: Make sure sharing is enabled on the host

On the machine hosting the share (or the relevant server settings):

• Network Discovery: On
• File and Printer Sharing: On
• Password-protected sharing: Usually On (recommended)

Step 3: Reset the Windows network stack (safe and often effective)

Run these in an elevated Command Prompt:

Reboot afterward.

Step 4: Check SMBv1 vs SMBv2/v3 status

If you suspect a legacy device is involved, confirm SMB settings using Microsoft’s guidance on SMB components and configuration.

Best outcome: the device supports SMBv2/v3 and you enable that on the device/server.
If it truly only supports SMBv1, enabling SMBv1 on the client may allow accessbut plan to upgrade ASAP.

Step 5: Try a resilient copy method for large transfers

If the error appears during big file copies (especially over Wi-Fi), use a tool that retries and resumes.
robocopy is built-in and unapologetically stubborn:

/Z enables restartable mode, and the retry/wait options help with brief dropouts.

Advanced Fixes (When the Basics Don’t Cut It)

Restart Workstation service (client-side SMB “reset button”)

On some systems, restarting the Windows Workstation service can restore access when SMB sessions get stuck.
This is commonly mentioned in real-world admin troubleshooting.

How: Run services.msc → find Workstation → Restart.

System file health checks (when Windows is acting… Windows)

If networking components are corrupted or misbehaving after updates or software installs, run:

Check for latency/timeouts and flaky links

Some vendors explicitly tie Error 64 / ERROR_NETNAME_DELETED to latency, timeouts, or the resource becoming unavailable mid-operation.

• If you’re on Wi-Fi: test on Ethernet.
• Replace questionable cables (yes, that one that’s been stepped on since 2019).
• Update network adapter drivers and router firmware if multiple devices show similar SMB drops.

Special Scenarios You Might Be In

If you see it while joining a domain

Microsoft documents domain join cases where connecting to the domain controller’s IPC share returns error 64 (0x40).

High-impact checks:

• Verify DNS on the client points to the domain controller (not a public DNS resolver).
• Ensure the client can reach the DC over required ports and SMB.
• Confirm time sync (large time drift can break authentication).

If you see it mapping cloud file shares (like Azure Files)

“System error 64” appears in SMB mapping scenarios where policies, SMB configuration, or access rules block the connectioneven when basic connectivity seems fine.

In those environments, focus on:

• Security policy and firewall rules (outbound SMB, restrictions on 445)
• Correct credentials and identity configuration
• Whether the environment blocks legacy SMB negotiation or enforces signing/encryption

If backups fail with this error

Backup tools using SMB repositories often throw this when connectivity drops mid-stream or the share becomes temporarily unavailable.
Many vendor knowledge bases treat it as an SMB connectivity stability issue (not “a corrupt backup file”).

How to Prevent It From Coming Back (Because Nobody Has Time for Sequels)

• Prefer SMBv2/v3 and upgrade legacy devices instead of relying on SMBv1.
• Use Ethernet for heavy file transfers and backups whenever possible.
• Disable aggressive sleep settings on PCs and NAS devices that host shares.
• Standardize naming (DNS records, static IPs for servers, consistent hostnames).
• Keep firewall rules intentional: allow File and Printer Sharing only on Private networks.
• Use robust transfer tools (like robocopy) for big, long-running operations.

Conclusion

“The specified network name is no longer available” looks dramatic, but it usually boils down to one of three things:
(1) the share/server dropped off the network,
(2) SMB negotiation/settings don’t match,
or (3) security/power-saving interrupted the session.

Start with reachability (ping, IP-based access), clear stale credentials, confirm sharing and firewall settings, and then move into SMB version checks.
If SMBv1 is involved, treat it as a temporary bridgenot your forever homebecause modern Windows increasingly assumes SMBv2/v3 for good reasons.

Real-World Experiences: What Troubleshooting Usually Looks Like (And Why It’s Not Your Fault)

In real environments, this error rarely shows up with a neat little label that says “Hello, I am caused by DNS.” It’s more like a mystery novel where the clues
are scattered across your router, Windows settings, and a NAS that quietly decided it deserves a midday nap.

One common scenario is the post-update surprise. A PC updates overnight, you come in the next morning, and suddenly the mapped drive that’s been
working for months starts failing. Usually nothing “broke” in your files; instead, Windows tightened something uplike network discovery behavior, firewall rules,
or SMB defaultswhile your older NAS is still living in the past. You test \ServerNameShare, it fails, but \192.168.1.50Share works,
and that’s your clue: the share is alive, but name resolution or discovery is off. Flushing DNS, rebooting the router, or fixing a static IP/DNS entry often ends
the drama.

Another frequent story is the Wi-Fi “looks fine” lie. Streaming video works, web browsing is snappy, and ping replies come backso the network must be okay,
right? Not always. SMB file transfers are sensitive to brief dropouts. A two-second Wi-Fi hiccup can ruin a large copy or a backup job and trigger error 64.
Switching the same machine to Ethernet magically “fixes” it, which feels like cheating… but it’s also the fastest way to prove the root cause is link stability.
When Ethernet resolves it, the long-term win is improving Wi-Fi signal, reducing interference, updating drivers, or scheduling heavy transfers for quieter network hours.

Then there’s the sleep setting sabotage. Laptops do what laptops do: they save power. NAS devices also try to be helpful by spinning down disks or entering low-power mode.
The problem is that SMB sessions don’t always appreciate surprise naps. You open a share after lunch and get the error because the device is still waking up, or the network adapter
was powered down. Disabling “Allow the computer to turn off this device to save power” on the network adapter and adjusting NAS sleep/spindown behavior often stops repeat failures,
especially in offices where shared folders are accessed intermittently.

A fourth pattern shows up in organizations: security software as an overprotective bouncer. Endpoint protection is supposed to keep you safe, but sometimes it blocks file-sharing
traffic, inspects it too aggressively, or changes behavior after an update. The clue here is consistency: a few machines fail while others work, or the error appears only when a specific
backup tool runs. Temporarily disabling the security layer for a test can confirm suspicionbut the real fix is adding a correct exception or adjusting policies, not leaving protections off.

Finally, don’t underestimate the stale credential gremlin. Windows may keep trying old usernames/passwords or cached sessions even after you “fixed” access on the server.
You remove the mapping, add it back, and it still failsuntil you clear Credential Manager entries and reconnect cleanly. It’s frustrating, but also one of the most satisfying fixes,
because once you delete the bad saved credentials, everything works like nothing ever happened (which is exactly how computers apologize).

The big takeaway from these real-world patterns is that you’re not looking for one magical checkbox. You’re narrowing it down:
Is it the path/name? Is it SMB compatibility? Is it stability/power? Is it security?
Once you identify which category you’re in, the solution gets a lot less mysteriousand a lot more permanent.