You're right in the middle of something. Maybe you're rendering a 4K video, or maybe you're just trying to open a massive Excel spreadsheet that some colleague sent over without any regard for your sanity. Then, it hits. That little gray box pops up with the most frustratingly vague sentence in the history of computing: there is not enough memory to complete this operation.
It’s annoying.
Honestly, it feels like a personal insult from your hardware. You know you have 16GB of RAM. You know you aren't running a NASA simulation. So why is your computer acting like it can't handle a simple task? The reality is that "memory" in Windows or macOS isn't just about how many sticks of RAM you bought. It’s a messy, complicated dance between physical hardware, virtual page files, and—quite often—lazy coding by software developers.
What Actually Happens When Your RAM "Runs Out"
Computers don't just "run out" of space like a closet. It's more like a busy kitchen. If the chef (the CPU) doesn't have enough counter space (the RAM) to chop vegetables, everything grinds to a halt. When you see the error that there is not enough memory to complete this operation, the system is basically saying it can't find a contiguous block of space to put the next piece of data.
Sometimes it isn't even about the total amount of RAM. It's about fragmentation.
Imagine having a parking lot with 100 spaces. If 50 cars are parked every other space, you still have 50 spots left, right? But if a giant bus pulls up needing five spaces in a row, it can't park. That's a memory leak in a nutshell. A program asks for a bit of memory, forgets to give it back when it’s done, and suddenly your system is full of tiny, unusable holes. Chrome is famous for this, but honestly, modern desktop apps built on Electron (like Discord or Slack) are just as guilty of gobbling up resources until the OS chokes.
The Secret Culprit: The Desktop Heap
Most people think about RAM, but Windows users often run into a very specific, old-school limit called the Desktop Heap. This is a tiny slice of memory dedicated to things like windows, menus, and icons.
You could have 128GB of RAM and still get an out-of-memory error if you have too many windows open. Why? Because the Desktop Heap is a fixed size. If you're someone who keeps 400 browser tabs and 50 folders open, you’re hitting a structural limit of the operating system that dates back to the early days of NT architecture. Microsoft has increased these limits over the years, but they aren't infinite.
32-Bit Limitations in a 64-Bit World
We live in a 64-bit world now. Most of us don't even think about it. But if you are using an older version of Excel—specifically the 32-bit version—it doesn't matter if your PC is a beast.
A 32-bit application can only "see" 2GB of RAM. Period.
If you try to load a massive data set into 32-bit Excel, you’ll get the "there is not enough memory to complete this operation" error every single time, even if your Task Manager says you have 90% of your system memory free. It’s like trying to pour a gallon of water into a pint glass. The solution here isn't buying more RAM; it’s uninstalling the 32-bit Office suite and installing the 64-bit version. It sounds simple, but you'd be surprised how many corporate IT departments still deploy 32-bit software by default for "compatibility" reasons.
The Virtual Memory and Page File Myth
"Just increase your page file!"
You've probably seen this advice on every tech forum since 1998. The page file (or swap space) is a chunk of your hard drive or SSD that the computer uses as "fake" RAM when the real stuff fills up.
Back when we used spinning mechanical hard drives, the page file was incredibly slow. Using it felt like wading through molasses. With modern NVMe SSDs, it’s much faster, but it’s still nowhere near the speed of actual DDR4 or DDR5 RAM. If your system is constantly hitting the page file, your performance will tank long before you see an error message.
However, if you've manually disabled your page file because you read somewhere that it "saves your SSD life," you’re actually making your system more prone to errors. Some programs insist on seeing a page file. If it’s missing or too small, they panic and throw the "not enough memory" error immediately, even if your physical RAM is half empty. Set it to "System Managed" and leave it alone. The engineers at Microsoft and Apple actually know what they're doing with memory management.
When Graphics Cards Get Involved
Sometimes the "operation" that can't be completed is a visual one. In gaming or video editing, the error might not be referring to system RAM at all, but rather VRAM—Video RAM.
Modern games are textures-heavy. If you're trying to run a game at 4K with Ultra settings on a card with only 8GB of VRAM, the buffer will overflow. The system tries to offload that data to your system RAM, but that transfer is slow. Eventually, the driver crashes, or the application gives up.
It’s worth checking your GPU usage in the Performance tab of Task Manager. If that "Dedicated GPU Memory" graph is a flat line at the top, that’s your bottleneck. Lower your texture quality or shadow resolution. It’s a bitter pill to swallow when you’ve spent a lot on a rig, but software requirements are outpacing hardware faster than ever.
Specific Fixes for Common Scenarios
Let's get practical. If you're staring at this error right now, walk through these steps in order. Don't just reboot and hope for the best, though that does solve 90% of cases by flushing the "zombie" processes that are holding onto memory.
1. The "Ghost" Process Hunt
Open Task Manager (Ctrl + Shift + Esc). Sort by the "Memory" column. You're looking for things that shouldn't be there. Found a background process for a printer you haven't used in three years? Kill it. Found a web browser helper that's using 4GB? Kill it.
2. The Excel "Big Grid" Problem
If you're getting this in Excel, try saving the file as an .xlsb (Binary Workbook). It’s more efficient. Also, check for "excessive formatting." Sometimes people accidentally format every single row in a spreadsheet (all 1,048,576 of them), and Excel tries to hold all that "nothingness" in memory. Clear all cells outside your actual data range.
3. Clipboard Bloat
Surprisingly, the clipboard can cause this. If you copied a massive high-resolution image or a huge block of data, it stays in the memory buffer. Pressing Win + V and clearing your clipboard history can sometimes instantly resolve the error in creative apps like Photoshop or Illustrator.
4. Temporary Files and Disk Space
This sounds counter-intuitive, but if your C: drive is almost full (less than 5GB free), Windows can't expand the page file. It hits a hard wall. You might have 32GB of RAM, but if the OS can't create the temporary scratch space it needs on the disk, it will tell you there's not enough memory. Delete your temp files. Empty the trash. Give your OS some room to breathe.
What Most People Get Wrong About Memory
There is a common misconception that "Free RAM is good RAM."
Actually, free RAM is wasted RAM.
MacOS and Linux are very aggressive about using every megabyte you have to cache files and speed up the UI. If you see 90% usage, don't panic. Panic only when you see the "Commit Charge" (in Windows) exceeding your physical limit. The error there is not enough memory to complete this operation occurs when the demand exceeds the total available pool (Physical + Virtual).
If you are a developer, this error usually points to a malloc failure. You're asking the kernel for a pointer to a memory address, and the kernel is saying "No." This is often caused by not checking the return value of your memory allocation calls, leading to a crash shortly after the error message appears.
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Beyond the Software: Hardware Failures
Is it possible your RAM is actually dying? Yes.
It’s rare, but failing memory modules can report incorrect capacities or cause addresses to become "unreachable." If you’re getting this error randomly, even when you aren't doing anything intensive, it’s time to run a diagnostic. Windows has a built-in tool called "Windows Memory Diagnostic," but the gold standard is still MemTest86. If you see a single red line in MemTest, your RAM is physically broken. No amount of settings-tweaking will fix that. You'll need to buy a new stick.
Actionable Steps to Clear the Error
Stop chasing "RAM cleaner" apps. They are mostly snake oil. They just force programs to move their data from fast RAM to the slow hard drive, making your computer feel "snappier" for five seconds before it becomes even slower. Instead, do this:
- Update your BIOS/UEFI. Manufacturers often release updates that improve memory stability and compatibility with high-capacity sticks.
- Check for Malware. Some miners run "headless" (without a window) and consume massive amounts of system resources. If your RAM usage is 80% and Task Manager doesn't show where it's going, you might have a hidden guest.
- Check the "Commit Limit." In Task Manager > Performance > Memory, look at "Committed." If the first number is very close to the second (e.g., 31.5/32.0 GB), your system is out of room to assign new tasks. Close applications until that first number drops significantly.
- Restart the "Explorer.exe" process. Sometimes the Windows UI itself gets stuck in a loop. Restarting it via Task Manager can refresh the Desktop Heap without a full reboot.
Ultimately, this error is a signal that your workflow has hit a ceiling. Whether that's a hardware ceiling or a software bug depends on what you were doing the moment it appeared. If it happens in one specific program, it’s a software issue. If it happens everywhere, it’s a system configuration or hardware issue. Treat it like a puzzle, not a disaster.
Start by clearing your temporary files and checking for 32-bit software bottlenecks. These are the most frequent causes in 2026. If you're still stuck, check your disk space for the page file expansion. Usually, the fix is simpler than buying new hardware.
To see exactly what is eating your memory at a granular level, download RAMMap from Microsoft’s Sysinternals suite. It shows you exactly how every byte is being used, including the "hidden" categories Task Manager won't show you. This tool is the final word on where your memory went. Use the "Empty" menu in RAMMap to manually clear the Working Sets or Standby List if you need an immediate, temporary fix without rebooting.