Support

What is checksum verification and why does it matter?

A checksum (or hash) is a unique fingerprint calculated from file contents. Even changing a single byte produces a completely different checksum. Verifying checksums ensures:

• File integrity: The download wasn't corrupted during transfer
• Authenticity: The file hasn't been modified or tampered with
• Security: No malware has been injected into the original file

Always verify checksums before running executable files, especially when downloading from third-party archives or mirrors.

How do I calculate a file's checksum?

Use built-in Windows tools to calculate SHA-256 checksums:

Get-FileHash filename.exe -Algorithm SHA256

certutil -hashfile filename.exe SHA256

The output shows the checksum value as a long hexadecimal string. Compare this exactly against published values—they must match character-for-character.

What if the checksum doesn't match?

A mismatched checksum indicates file corruption or modification. Take these steps:

1. Delete the file immediately—do not run it
2. Try downloading again from the same source (transfer errors can occur)
3. If it still doesn't match, try a different download source
4. Report the mismatch to the source site if you suspect tampering

Never ignore checksum mismatches. They exist specifically to warn you of problems.

What if no checksums are published?

Unfortunately, many classic freeware titles lack published checksums because the original authors didn't provide them. In these cases:

• Download only from well-known, reputable archives
• Scan the file with up-to-date antivirus software
• Check file size against documented values (mismatched sizes often indicate repackaging or bundling)
• Use VirusTotal or similar services to check if others have scanned the same file
• Be cautious—without checksums, you're trusting the download source completely

Will these tools run on Windows 10 or Windows 11?

Most classic space visualization tools were designed for Windows 95/98/XP but many still run on modern Windows versions. Compatibility varies by specific tool:

• Usually compatible: Tools that use standard Win32 APIs typically work without modification on Windows 10/11
• May need compatibility mode: Some tools require running in compatibility mode for Windows XP or Windows 7
• May have issues: Tools using deprecated DirectX versions or 16-bit installers may not work on 64-bit Windows

Check individual product pages for specific compatibility notes.

How do I use Windows Compatibility Mode?

To run older software in compatibility mode:

1. Right-click the executable file (.exe)
2. Select Properties
3. Click the Compatibility tab
4. Check "Run this program in compatibility mode for:"
5. Select an older Windows version from the dropdown (try Windows XP SP3 or Windows 7 first)
6. Optionally enable additional settings like "Run as administrator"
7. Click OK and try running the program

If one compatibility mode doesn't work, try others—sometimes Windows 98 or Windows 7 mode resolves issues.

What if it still won't run?

If compatibility mode fails, consider these alternatives:

• Virtual machine: Run an older Windows version (like Windows XP) in VirtualBox or VMware to execute legacy software
• DOSBox/Wine: For very old DOS-based tools, DOSBox may work better than native Windows compatibility
• Check for updates: Some tools received unofficial patches or updated versions that resolve compatibility issues

Why does my antivirus flag these tools?

Antivirus false positives on classic freeware occur for several reasons:

• Unsigned binaries: Old freeware predates code-signing, so files lack digital signatures modern AV expects
• Uncommon packing: Some tools use compression or packing that resembles malware obfuscation techniques
• Heuristic detection: Behaviors like directly accessing graphics hardware or system files trigger heuristic warnings
• Low popularity: Files downloaded by few users receive less trust from reputation-based AV systems

However, false positives don't guarantee safety. Always verify downloads carefully.

How do I know if it's a false positive or real malware?

Validate files using multiple methods:

1. Check checksums: If published checksums match, the file is authentic (though not guaranteed safe if the original itself was compromised)
2. Use VirusTotal: Upload the file to VirusTotal to scan with 60+ antivirus engines. One or two detections may be false positives; 10+ strong detections usually indicate real malware
3. Check detection names: Generic names like "Suspicious.Generic" or "PUA (Potentially Unwanted Application)" often indicate false positives. Specific malware family names suggest real threats
4. Verify the source: Downloads from reputable archives (Internet Archive, SourceForge classics section) are more trustworthy than random file-sharing sites
5. Compare file sizes: If the file size doesn't match documented values, it may be a repackaged or modified version

Should I disable antivirus to run these tools?

No. Disabling antivirus protection creates security risks. Instead:

• If you've verified the file is safe, create an antivirus exclusion for that specific file (not the entire downloads folder)
• Use Windows Defender's "Allow on device" option after thorough verification
• Run suspicious files in an isolated virtual machine or sandboxed environment first

Never disable antivirus system-wide just to run a single program.

Where can I find more documentation for these tools?

Documentation is available in several places:

• Product pages: Each tool has a dedicated product page with feature descriptions and specifications
• Download hub: The download hub provides comprehensive safety and verification guidance
• Download info pages: Each tool's .exe page (e.g., earth3d.exe) includes verification details and quick reference information

How do I report a broken link or outdated information?

Use the contact form to report:

• Broken external links or dead download sources
• Outdated compatibility information
• Incorrect checksums or file details
• Suggestions for additional information or resources

Include the page URL and specific issue in your message so we can verify and update accordingly.

Can you help me run or configure a specific tool?

This site provides reference information and safety guidance but doesn't offer end-user technical support for running specific software. For tool-specific help:

• Check if the original tool included a README or help file
• Search online communities and forums for user discussions (many classic tools have dedicated fan communities)
• Try compatibility mode or virtual machines for stubborn legacy software

Why don't you host the executable files directly?

This site focuses on documentation, verification guidance, and safety information rather than file distribution. This approach:

• Reduces security and liability concerns associated with file hosting
• Ensures users understand verification practices before downloading
• Points users to established archives with proper licensing and attribution

Download guidance pages link to reputable sources when available.