C drive is full. What should I delete to clean up C drive safely?

C drive is full -- Similar to the "Disk Full" error, this indicates that there's not enough free space on the disk to proceed with the operation.

Using BleachBit can be an effective way to free up space when C drive is full. It’s a free, open-source cleaning tool that helps remove unnecessary files and clean up system clutter. Here's what you should know about using BleachBit:

How to Use BleachBit Safely If C Drive is full:

1. Download from Official Site: Always get BleachBit from its official website to avoid malware.
2. Run as Administrator: Right-click the program and select "Run as administrator" to allow deeper cleaning.
3. Review the Cleaning Options:
   Carefully check the items you want to delete.
   Avoid cleaning things you might need later unless you are sure.
4. Perform a Backup (Optional): BleachBit can create backups of certain files before deletion.
   Run the Cleanup: Click "Clean" and wait for the process to complete.

Important Precautions

Avoid Deleting Personal Files: BleachBit mainly deletes system and application cache; it does not delete personal documents unless explicitly selected.

Be Careful with Deep Cleaning: Some options, like cleaning system logs or free disk space, should be used cautiously.

Check Before Confirming: Always review what will be deleted before executing the cleanup.

When your C drive is full (especially with only 6GB free), certain actions can lead to catastrophic errors. When you're desperate for space, it's tempting to hunt for the biggest files and delete them. But if you delete the wrong system file—even one you think is "just a temp file"—Windows might not start next time.

1. Don't Let Windows Update Run or Restart for Updates
Windows Update needs breathing room—like 10–20GB—to unpack and install updates.
If it starts with only a few GB free, it’ll fail halfway through and leave your system in update limbo: not the old version, not the new version, just broken.

2. Don't Force a Shutdown or Restart While Things Are Hanging
When the drive is full, everything slows down—programs freeze, Explorer stops responding. 
If you hold the power button to force a shutdown, you risk cutting off Windows while it's writing something important. That's how you corrupt system files, user profiles, or the registry.

3. Don't Run "Cleaner" Apps Aggressively
Apps like Third-party software promise to free up space, but when the drive is critically low, they can remove files Windows is actively using or delete restore points you might need.

4. Don't Mess with Virtual Memory Settings
Yes, you can move the pagefile to another drive—but don't disable it entirely.
Windows uses it as emergency RAM. Without it, programs will crash, and you could get memory errors that freeze the whole system.

The C disk is full is not a difficult problem, but it should be noted that: Always back up important data before deleting large files or performing cleanup operations, especially if you're not sure about their importance. Some cache or temporary files may be needed for ongoing processes or applications. Deleting them indiscriminately might cause apps to malfunction or lose session data. Do not manually delete files from application directories unless the program is uninstalled properly. This can leave residual files or corrupt the application.

Moving the pagefile (virtual memory) to another drive, such as D:, can help free up space if C drive is full. Additionally, it can improve performance if your D: drive is faster or less full. Here’s how to do it:

How to Move the Pagefile to D: Drive on Windows

1. Open System Properties
    Press Windows + R, type sysdm.cpl, and press Enter.

2. Go to the Advanced Tab
   Click on the Advanced tab.
   Under Performance, click Settings.

3. Access Virtual Memory Settings
   In the Performance Options window, go to the Advanced tab.
   Click Change under Virtual memory.

4. Configure the Pagefile on D:
   Uncheck Automatically manage paging file size for all drives.
   Select your C: drive, then choose No paging file.
   Select your D: drive, then click Custom size.
   Enter the initial and maximum size (usually 1.5 to 3 times your RAM). For example:
   Initial size: 4096 MB (4 GB)
   Maximum size: 8192 MB (8 GB)

5. Apply and Restart
   Click Set, then OK on all windows.
   Restart your computer to apply the changes. Your computer will no longer remind you that the C drive is full.

NirCmd is a small command-line utility that allows you to perform various system tasks easily. If your C drive is full, you can use NirCmd to free up space by deleting unnecessary files, clearing temporary files, or managing system resources.

Here are some ways you can use NirCmd if C drive is Full:

1. Delete Specific Large Files or Folders
You can delete specific files or folders you no longer need, for example:

nircmd deletefile "C:\Path\to\file\or\folder\*"

Note: Be very careful with delete commands to avoid deleting important system files.

2. Automate Cleanup Tasks

You can create scripts that run cleanup commands automatically to free space regularly.

3. Clear Recycle Bin
Emptying the Recycle Bin can free significant space:

nircmd emptybin

If your C drive is full, here are some steps to help you free up space:

• Check for updates: Ensure your Windows is up-to-date, as newer versions often include features to help manage disk space.
• Empty the Recycle Bin: This might sound obvious, but it's easy to overlook. Make sure to empty the Recycle Bin regularly.
• Reinstall Windows: If none of the above steps help, you might want to consider reinstalling Windows. This will give you a clean slate and free up space on your C drive.
• Extend the C drive: If you have another drive on your computer, you can extend the C drive by using the disk management tool.

Before you start deleting:

Backup your data: Once your C drive is full, then deleting unnecessary data is inevitable. Ensure that you have a recent backup of your important files and documents. You can use an external hard drive, cloud storage (e.g., OneDrive, Google Drive), or a backup software.

Identify essential files: Make a list of the files and folders you need to keep, such as:

Documents, videos, and photos

Installed programs and their folders

Windows system files and folders (e.g., Windows, Program Files, Users)

Backup files and folders

Cleaning up a C drive can be a daunting task if C drive is full, but I'm here to guide you through it safely. Before we begin, let's emphasize the importance of being cautious: deleting the wrong files can indeed cause problems, so we'll take a step-by-step approach.

What to do if C drive is full：

1. Delete temporary files if C drive is full:
Press the Windows key + R to open the Run dialog box.
Type %temp% and press Enter to open the Temp folder.
Delete any files and subfolders in the Temp folder.

2. Delete Windows update files:
Open File Explorer and navigate to the Windows Update folder (C:\Windows\SoftwareDistribution\Download).
Delete any files in the Download folder.
Be cautious not to delete files in the SoftwareDistribution folder.

3. Delete old system folders:
Open File Explorer and navigate to the C drive.
Look for old system folders, such as System Volume Information, Windows.old, or other folders with old dates.
Be cautious not to delete folders containing essential files, such as Windows, Program Files, or Users.

4. Check the Disk Cleanup tool:
Press the Windows key + R to open the Run dialog box.
Type cleanmgr and press Enter to open the Disk Cleanup tool.
Follow the on-screen instructions to delete unnecessary files and system files.