VMware Not Enough Physical Memory Error Fix

The “Not enough physical memory is available” error in VMware Workstation or Player appears when the host system cannot allocate the RAM your virtual machine requests. The fix is to reduce the VM’s memory allocation, close memory-heavy host applications, and adjust VMware’s memory settings so it can use a swap file. This guide walks you through the exact steps and explains why the error happens so you can prevent it from recurring.

What Causes the Error

VMware reserves physical RAM for each running virtual machine. When you start a VM, the hypervisor tries to lock the requested memory (plus a small overhead) from the host’s available RAM. If Windows or other applications have already consumed most of the physical memory, VMware cannot reserve the required amount and throws the error. The condition is more common on systems with 8 GB or less RAM, or when you have multiple VMs running simultaneously.

The error message can appear in different forms, such as “Not enough physical memory is available to power on this virtual machine” or “Failed to lock memory.” Both point to the same root cause: the host cannot provide the contiguous physical memory block VMware needs.

Check Your Host Memory First

Before changing any settings, confirm how much RAM is actually free on your Windows host. Open Task Manager (Ctrl+Shift+Esc), go to the Performance tab, and look at the Memory section. Note the “In use” and “Available” values. If available memory is below the VM’s configured RAM, that’s your problem.

• Close unnecessary applications, especially browsers with many tabs, video editors, or other VMs.
• Check for background processes that eat RAM, such as antivirus scans or cloud sync clients.
• If you’re using a laptop, make sure it’s plugged in – some power plans reduce available memory for performance.

If you have less than 4 GB free, you’ll need to either close more programs or reduce the VM’s memory allocation.

Reduce the VM’s Memory Allocation

The most direct fix is to lower the amount of RAM assigned to the virtual machine. Open VMware, select the VM, and click Edit virtual machine settings. Under the Memory section, reduce the value to something your host can realistically provide. For example, if your host has 8 GB total and Windows uses 3 GB, set the VM to 2 GB or 3 GB instead of 4 GB.

Be careful not to set it too low – the guest OS (especially Windows 10/11) will become sluggish if it has less than 2 GB. A good rule is to leave at least 2–3 GB of RAM for the host OS after allocating to the VM. If you’re running a lightweight Linux VM, 1 GB may be enough.

After changing the setting, click OK and try powering on the VM again.

Adjust VMware’s Memory Settings

VMware has a global preference that controls how it handles memory when the host is tight. Go to Edit > Preferences (or File > Preferences) and select the Memory tab. You’ll see a slider for “Additional memory” with options:

• Fit all virtual machine memory into reserved RAM – this forces VMware to use only physical RAM, which can cause the error if there isn’t enough.
• Allow some virtual machine memory to be swapped – lets VMware use the host’s pagefile as a fallback. This is the recommended setting for most users.
• Allow most virtual machine memory to be swapped – uses more pagefile, which may slow down the VM but avoids the error.

Choose the middle option (“Allow some virtual machine memory to be swapped”) and click OK. This tells VMware it can use the Windows pagefile when physical RAM is scarce, which prevents the error in many cases.

Increase the Windows Pagefile

If VMware is allowed to swap, it needs a sufficiently large pagefile on the host. Windows manages the pagefile automatically by default, but you can increase it manually to give VMware more headroom. Go to Control Panel > System > Advanced system settings > Settings (under Performance) > Advanced tab > Change under Virtual memory.

Uncheck “Automatically manage paging file size for all drives,” select your C: drive, choose “Custom size,” and set an initial and maximum size. A common recommendation is 1.5 times your RAM for the initial size and 3 times for the maximum, but you can set both to the same value to avoid fragmentation. For example, with 8 GB RAM, set initial to 12288 MB and max to 12288 MB. Click Set, then OK, and restart Windows.

Be aware that swapping to disk is much slower than RAM, so the VM may run slower. This is a trade-off, but it’s better than not being able to start the VM at all.

Other Quick Fixes to Try

If the above steps don’t resolve the issue, try these additional measures:

• Disable Memory Trimming – In VMware preferences, under Memory, uncheck “Reserve all guest memory” if it’s checked. This lets VMware release unused memory back to the host.
• Update VMware – Older versions may have bugs related to memory management. Install the latest update from the official VMware website.
• Check for Windows Memory Leaks – If your host’s memory usage climbs over time, a driver or application may be leaking memory. Restart Windows to clear it, then monitor Task Manager.
• Reduce the number of running VMs – Each VM consumes RAM. If you have multiple VMs running, pause or shut down the ones you’re not using.
• Use a lighter guest OS – If your VM is running a heavy OS, consider switching to a lighter distribution to reduce memory requirements.

If none of these work, the ultimate solution is to add more physical RAM to your computer. This is the only way to guarantee enough memory for large VMs without performance degradation.

Frequently Asked Questions

Why does the error say “failed to lock memory”?

This is a specific variant of the same problem. VMware tries to lock the VM’s memory in physical RAM so it can’t be paged out, but if the host can’t provide a large enough contiguous block, the lock fails. The fix is the same: reduce the VM’s memory, close other programs, or allow VMware to swap.

Can I run a 64-bit VM with 4 GB RAM on a host with 8 GB?

Yes, but you’ll need to be careful. Windows will use about 2–3 GB, leaving 5–6 GB for the VM. That’s enough for a 4 GB VM, but you may need to close other applications. If you see the error, reduce the VM to 3 GB or increase your host RAM.

Does increasing the pagefile slow down the VM?

Yes, significantly. The pagefile is on your hard drive or SSD, which is much slower than RAM. If VMware swaps memory to disk, the VM will experience lag, especially when the guest OS is under load. It’s a temporary fix, not a performance solution.

Is it safe to set the VM memory to the maximum recommended by VMware?

VMware’s recommended maximum is based on your host’s total RAM, but it doesn’t account for the host OS and other applications. You should always leave enough RAM for the host to run smoothly. A good rule is to allocate no more than 50-75% of your physical RAM to VMs.

Why does the error appear even when I have free RAM?

Sometimes VMware requires a contiguous block of physical memory, and even if you have free RAM, it may be fragmented. This is more common on systems that have been running for a long time. Restarting Windows can help consolidate memory, or you can enable VMware’s memory swapping option.

Can I use a memory ballooning feature to fix this?

VMware’s memory ballooning is a feature that reclaims memory from idle VMs, but it’s not a fix for the “not enough physical memory” error. Ballooning only works when the VM is running, not when you’re trying to start it. The error occurs during startup, so you need to free up memory before powering on.

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