Fix Slow Access to Network Shared Folders in Windows 10

Slow access to network shared folders in Windows 10 usually stems from incorrect SMB protocol settings, stale credentials, or Windows features like SMB1 and auto-tuning. The fastest fix is to disable SMB1, enable SMB2/3, and adjust the SMB client’s auto-disconnect timeout; below are the exact steps and the reasoning behind them.

Why Network Folder Access Slows Down

When you open a shared folder over the network, Windows 10 uses the Server Message Block (SMB) protocol to transfer data. The version of SMB in use matters a lot: SMB1 is ancient, slow, and insecure, while SMB2 and SMB3 are modern, faster, and more reliable. If your network has any device that still negotiates SMB1 (like an old NAS or a legacy printer), Windows may fall back to it, causing noticeable lag when browsing folders or opening files.

Another common culprit is the “Auto disconnect” feature. By default, Windows 10 disconnects idle SMB sessions after 15 minutes. When you try to access the folder again, Windows has to reconnect, which can take several seconds. This feels like “slow access” even though the network itself is fine.

Check Which SMB Version You’re Using

Before making changes, find out whether SMB1 is still enabled on your system. Open PowerShell as Administrator and run:

Get-SmbServerConfiguration | Select EnableSMB1Protocol

If it returns True, SMB1 is enabled. Also check the SMB client:

Get-SmbClientConfiguration | Select EnableSMB1Protocol

On a clean Windows 10 install, SMB1 is disabled by default, but it can be re‑enabled by legacy software or manual configuration. If either shows True, disable it using the steps below.

Disable SMB1 and Ensure SMB2/3 Is Active

Disabling SMB1 is the single most effective fix for slow network folder access. It removes the fallback to a slow, insecure protocol and forces Windows to use SMB2 or SMB3, which are much faster and more secure.

1. Open Control Panel → Programs → Turn Windows features on or off.
2. Scroll down to SMB 1.0/CIFS File Sharing Support.
3. Uncheck the box (if it’s checked) and click OK.
4. Restart your PC.

Alternatively, in PowerShell (Admin):

Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol

After the restart, verify that SMB2/3 is active. Windows 10 automatically enables SMB2/3 when SMB1 is off, so no further action is needed. You can confirm with:

Get-SmbServerConfiguration | Select EnableSMB2Protocol

It should return True.

Adjust the Auto-Disconnect Timeout

If your folders are slow to open after being idle for a while, the 15‑minute auto‑disconnect is likely the cause. You can increase the timeout or disable it entirely. Open PowerShell as Administrator and run:

Set-SmbClientConfiguration -AutodisconnectTimeout 60

This sets the timeout to 60 minutes. To disable auto‑disconnect completely, use -AutodisconnectTimeout 0. Note that a value of 0 means the session never times out, which can be a security risk on public networks. For a typical office or home network, 60 minutes is a good balance.

Clear Stale Credentials and Reconnect

Sometimes the slowdown is caused by Windows trying to use outdated credentials. If you’ve changed your password or the server’s permissions, Windows may hang while retrying the old login. To fix this, open Credential Manager:

1. Go to Control Panel → User Accounts → Credential Manager.
2. Click Windows Credentials.
3. Find any entries under Generic Credentials that relate to the server or shared folder.
4. Remove them, then reconnect to the share and enter your current password.

This forces Windows to use fresh credentials instead of a cached, possibly invalid one.

Disable IPv6 or Set a Static IP (If Needed)

Windows 10 sometimes tries IPv6 first, and if your network doesn’t handle it well, it can cause delays. You can disable IPv6 on the network adapter to force IPv4, which is often faster on local networks. However, this is not always the cause, so try other fixes first. If you do want to test, go to Network Connections → right‑click your adapter → Properties → uncheck Internet Protocol Version 6 (TCP/IPv6).

Another quick test: assign a static IP to your PC instead of using DHCP. This eliminates the delay of DHCP lease renewal, but it’s rarely the main issue. Only do this if you’re comfortable with networking basics.

Check Network Adapter Settings and Drivers

Outdated or misconfigured network drivers can cause slow SMB transfers. Update your network adapter driver from the manufacturer’s website, not just through Windows Update. Also, in the adapter’s properties, look for a setting called Large Send Offload or Green Ethernet. Disabling these can sometimes improve SMB performance, especially on older hardware.

To test if the driver is the problem, temporarily disable the adapter’s power saving mode: Device Manager → right‑click your network adapter → Properties → Power Management → uncheck Allow the computer to turn off this device to save power.

Frequently Asked Questions

Why is my network folder slow only when opening files?

This often points to SMB1 being used, or to the file itself being large and the network being slow. Check the SMB version as described above. Also, try copying a file to your local disk and see if the speed improves; if not, the bottleneck is the network or the server.

Is it safe to disable SMB1?

Yes, in fact it’s recommended. SMB1 is insecure and vulnerable to malware like WannaCry. Modern Windows and most NAS devices support SMB2/3, so disabling SMB1 rarely breaks anything. Only old devices (pre‑2007) might need it, and those should be upgraded or isolated.

Will these changes affect other computers on my network?

No, these changes only affect your Windows 10 machine. The server and other clients are unaffected. However, if the server is also Windows 10, you might want to apply the same fixes there for consistency.

What if the folder is still slow after disabling SMB1?

Try the auto‑disconnect timeout fix, clear credentials, and update your network driver. If the problem persists, test with a direct Ethernet cable instead of Wi‑Fi, as Wi‑Fi interference or weak signal is a common cause of slow network access.

Can I use Group Policy to apply these settings to multiple PCs?

Yes, you can use Group Policy to disable SMB1 and set the auto‑disconnect timeout across an entire domain. The settings are under Computer Configuration → Administrative Templates → Network → Lanman Workstation. This is useful for IT administrators managing many machines.

Why does the first access after boot take longer?

This is normal because the network stack is initializing and the SMB session is being established. You can reduce it by disabling IPv6 and setting a static IP, but it’s usually not worth the effort unless the delay is extreme (over 10 seconds).

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