[With Pro Tips] 7 Ways to Speed Up Opening Large Files on Windows

Illustration for a Windows tutorial about speeding up the opening of large files. A laptop displays a “LOADING…” screen, next to a file icon and a sad emoji, with bold text reading “Windows Slow Opening Large File – Improve Slow 7 Ways” on a blue background.

Have you ever tried to open a multi-gigabyte video or a massive CSV file, only to wait… and wait… and wait?

If you use Windows, you’ve probably run into this at least once.

But here’s the good news: you don’t have to just live with it. While you might not get instant speed, there are several practical ways to greatly improve how quickly large files open on your computer.

In this guide, we’ll walk you through seven effective ways to reduce slow loading times and help your PC handle heavy files more smoothly.

1. Reevaluate Your Storage: Upgrade from HDD to SSD

The type of storage device your file is saved on makes a big difference. If you’re still using an HDD (hard disk drive), switching to an SSD (solid-state drive) can increase loading speed dramatically—especially with large files that require fast random access. SSDs are now standard in modern systems for good reason.

2. Use Lightweight Apps That Handle Large Files Better

Default apps in Windows aren’t always the best at dealing with massive files. Try switching to specialized lightweight tools:

  • For large CSV files: EmEditor, Notepad++
  • For video playback: VLC Media Player
  • For PDF files: SumatraPDF

These apps are optimized for speed and can handle heavy files much more efficiently.

3. Close Background Apps and Clear Temporary Files

When your PC is running multiple programs at once, it can become overloaded. This slows down everything, including file loading.

Open Task Manager (Ctrl + Shift + Esc), check which programs are using up memory or disk space, and close anything unnecessary. Rebooting regularly also helps clear out cache and system clutter.

4. Exclude Trusted Files from Windows Defender Scanning (Temporarily)

Windows Defender often scans files in real time when you open them. While this is important for safety, it can slow things down for large files.

If the file is safe and trustworthy, you can temporarily add it to the exclusion list in Defender’s settings. Just remember to turn scanning back on afterward.

Note: Never use this method for suspicious or unknown files.

5. Avoid Opening Files from Cloud or Network Drives

Opening files directly from OneDrive, Google Drive, or a NAS (network-attached storage) can introduce delays due to syncing and network speed.

Instead, copy the file to your local drive (e.g., your desktop) before opening it. This simple step alone can greatly improve speed.

6. Adjust Virtual Memory Settings If You’re Low on RAM

If your PC doesn’t have much physical memory (RAM), Windows relies on virtual memory using your hard drive—which is slower.

If you have 8GB or less RAM, go to:

System > Advanced system settings > Performance settings > Virtual memory

…and manually increase the size. This can help reduce lag when opening large files.

Consider Upgrading Your RAM

Many slowdowns simply come from not having enough memory. Upgrading RAM is a very effective fix.

You should consider upgrading if:

  • You use multiple programs at once and have 8GB or less RAM
  • You work with large Excel files, CAD software, or video editing tools
  • You often keep dozens of browser tabs open

Modern systems with 16GB or more feel much faster overall. And while upgrading RAM sounds technical, it’s surprisingly easy for many desktop PCs (and some laptops). You can even find helpful videos online if you want to try it yourself. Or, ask a PC shop—it’s usually affordable.

7. Disable the Preview Pane in File Explorer

In File Explorer, simply selecting a large PDF or image can cause a preview to load—and freeze your system temporarily.

To fix this, open Explorer and disable the Preview Pane under the “View” menu.

This is especially helpful when dealing with large media files.

Bonus: What Makes a File “Heavy”? It’s Not Just the Size

A file can feel “heavy” even if its size doesn’t seem outrageous. Why? Structure matters too.

Common causes of file slowness include:

  • Embedded images, videos, or fonts in Word or Excel
  • Massive spreadsheets with too many formulas or links
  • Text files with no line breaks (millions of characters in a single line)
  • Custom compression formats that require heavy decoding

So, even a 30MB file can be more troublesome than a 1GB video, depending on what’s inside.

Pro Tip: Try a RAM Disk (Advanced Users Only)

If you have plenty of memory (16GB or more), you can create a RAM disk—a virtual drive that exists entirely in RAM. It’s much faster than even an SSD.

By placing your large files on a RAM disk temporarily, you can open and process them faster.

Important: Save your work before shutting down—RAM disks are wiped when the PC is turned off.

Extra Tips for Creators: Save Files in Faster Formats

If you create or edit large files often, you can reduce load times by:

  • Saving Excel files as binary format (.xlsb)
  • Optimizing PDF files (reduce resolution or embedded metadata)
  • Splitting CSV files into multiple smaller files (e.g., by month or year)

Summary: You Have More Control Than You Think

You don’t need to apply all these tips at once. Even one or two adjustments—like switching to a faster app or saving files locally—can make a big difference.

ActionWhat to DoEffectiveness
Upgrade to SSDSwitch from HDD to SSD for major speed increase★★★★★
Use lightweight appsUse Notepad++, EmEditor, VLC, etc.★★★★☆
Close unnecessary appsShut them via Task Manager★★★☆☆
Set Defender exclusionsExclude trusted files temporarily★★★☆☆
Copy locallyOpen files from Desktop or C: instead of network★★★★☆
Adjust virtual memoryCustomize if you have 8 GB or less RAM★★★☆☆
Disable Explorer previewTurn off Preview pane in File Explorer★★★☆☆
Upgrade RAMIncrease from ≤8 GB to 16 GB+★★★★★

Don’t feel like you need to do everything at once.

Start with the tweaks that suit your setup. Little by little, the belief that “opening big files always takes forever” may become a thing of the past.

A Few More Tips:

  • Use an external SSD to separate your work files and archives for faster workflows.
  • Try ReadyBoost (using a USB drive as virtual memory)—it helps a bit on older systems (less effective if you already use an SSD).

Why This Matters

While many users assume slow load times are inevitable, these user-level optimizations show how much control you actually have.

Upgrading to an SSD or adding RAM delivers long-term productivity benefits with minimal effort. Take one or two steps from this guide—and get ready for a smoother, faster Windows experience!

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