PE API Replacer - Release Installation Guide

📦 What's Included

This release contains a fully packaged, portable application with pre-built native libraries for multiple architectures and runtimes. No additional installation or compilation required.

Package Contents

pe-api-replacer-v1.0-release/
├── api_patcher.exe                 # Main application (PyInstaller compiled)
├── config.py                       # Configuration file (optional, for advanced users)
├── README.md                       # This file
│
├── 📂 API/                         # Pre-compiled replacement DLLs
│   ├── 📂 exinet/
│   │   ├── 📂 ucrt/                # Universal C Runtime version
│   │   │   ├── x32/
│   │   │   │   └── exinet.dll
│   │   │   ├── x64/
│   │   │   │   └── exinet.dll
│   │   │   └── arm64/
│   │   │       └── exinet.dll
│   │   │
│   │   └── 📂 msvcrt/              # MSVC Runtime version (legacy)
│   │       ├── x32/
│   │       │   └── exinet.dll
│   │       ├── x64/
│   │       │   └── exinet.dll
│   │       └── arm64/
│   │           └── exinet.dll
│   │
│   ├── 📂 exhttp/
│   │   ├── 📂 ucrt/
│   │   │   ├── x32/
│   │   │   ├── x64/
│   │   │   └── arm64/
│   │   └── 📂 msvcrt/
│   │       ├── x32/
│   │       ├── x64/
│   │       └── arm64/
│   │
│   ├── 📂 exws2/
│   │   ├── 📂 ucrt/
│   │   │   ├── x32/
│   │   │   ├── x64/
│   │   │   └── arm64/
│   │   └── 📂 msvcrt/
│   │       ├── x32/
│   │       ├── x64/
│   │       └── arm64/
│   │
│   └── 📂 [other_api_libs]/
│       ├── 📂 ucrt/
│       │   ├── x32/
│       │   ├── x64/
│       │   └── arm64/
│       └── 📂 msvcrt/
│           ├── x32/
│           ├── x64/
│           └── arm64/
│
└── 📄 CHANGELOG.md                 # Version history

🚀 Quick Start

Windows

Extract the archive to your desired location
```
C:\Program Files\PE-API-Replacer\
```
Run the application
- Double-click api_patcher.exe
- Administrator privileges may be requested (required for file modifications)
Select your files and configure options
- Click "Add Files" or "Add Folder"
- Choose APIs to replace
- Configure backup/overwrite settings
- Click "Start Patching"

macOS / Linux

While the core Python code is cross-platform, the pre-built executable is Windows-only. To run on macOS/Linux:

# Ensure Python 3.10+ is installed
python3 --version

# Install dependencies
pip3 install PyQt6 pefile

# Run from source
python3 api_patcher.py

📁 Installing Replacement Libraries (Optional)

The replacement DLL files are optional and only needed if you want custom API interception. Choose your runtime environment and architecture.

Selecting the Right Runtime

UCRT (Universal C Runtime) - Recommended for Windows 10/11 and modern systems
MSVCRT (Legacy) - For older Windows versions or systems without UCRT

Installation by Architecture

For 32-bit Applications (SysWOW64)

Choose your runtime, then copy x32 DLLs:

UCRT (Recommended):

Copy-Item -Path "API\exinet\ucrt\x32\*.dll" -Destination "C:\Windows\SysWOW64\" -Force
Copy-Item -Path "API\exhttp\ucrt\x32\*.dll" -Destination "C:\Windows\SysWOW64\" -Force
Copy-Item -Path "API\exws2\ucrt\x32\*.dll" -Destination "C:\Windows\SysWOW64\" -Force
# ... repeat for other API libraries

MSVCRT (Legacy):

Copy-Item -Path "API\exinet\msvcrt\x32\*.dll" -Destination "C:\Windows\SysWOW64\" -Force
Copy-Item -Path "API\exhttp\msvcrt\x32\*.dll" -Destination "C:\Windows\SysWOW64\" -Force
# ... repeat for other API libraries

For 64-bit Applications (System32)

Choose your runtime, then copy x64 DLLs:

UCRT (Recommended):

Copy-Item -Path "API\exinet\ucrt\x64\*.dll" -Destination "C:\Windows\System32\" -Force
Copy-Item -Path "API\exhttp\ucrt\x64\*.dll" -Destination "C:\Windows\System32\" -Force
Copy-Item -Path "API\exws2\ucrt\x64\*.dll" -Destination "C:\Windows\System32\" -Force
# ... repeat for other API libraries

MSVCRT (Legacy):

Copy-Item -Path "API\exinet\msvcrt\x64\*.dll" -Destination "C:\Windows\System32\" -Force
Copy-Item -Path "API\exhttp\msvcrt\x64\*.dll" -Destination "C:\Windows\System32\" -Force
# ... repeat for other API libraries

For ARM64 Windows Devices

Choose your runtime, then copy ARM64 DLLs to System32:

UCRT (Recommended):

Copy-Item -Path "API\exinet\ucrt\arm64\*.dll" -Destination "C:\Windows\System32\" -Force
Copy-Item -Path "API\exhttp\ucrt\arm64\*.dll" -Destination "C:\Windows\System32\" -Force
# ... repeat for other API libraries

MSVCRT (Legacy):

Copy-Item -Path "API\exinet\msvcrt\arm64\*.dll" -Destination "C:\Windows\System32\" -Force
Copy-Item -Path "API\exhttp\msvcrt\arm64\*.dll" -Destination "C:\Windows\System32\" -Force
# ... repeat for other API libraries

Required: Run PowerShell as Administrator for System32/SysWOW64 operations.

🌍 Language Support

Current Release (v1.0)

Ukrainian (Українська) - Primary language

Multilingual Release (Coming Soon)

An updated version with multiple language support will be released shortly, including:

English
Ukrainian
Additional languages (TBD)

If the Ukrainian interface is not suitable for your needs, a full English translation will be available upon request without any difficulty.

⚙️ Configuration

The config.py file contains API replacement definitions. For most users, the default configuration is sufficient.

For Advanced Users

Edit config.py to add custom API replacements:

DLL_REPLACEMENTS = {
    1: {'name': 'CUSTOM_API', 'replacements': {
        b'ORIGINAL.DLL': b'REPLACE.DLL\x00',
        b'original.dll': b'replace.dll\x00',
    }},
}

Important: Replacement length must equal original length. Pad with \x00 if needed.

After editing, place config.py in the same directory as api_patcher.exe for changes to take effect.

🔧 System Requirements

OS: Windows 10/11 (x86-64, x86-32, or ARM64)
RAM: Minimum 512 MB (1 GB recommended for batch operations)
Disk Space: 50 MB for application + storage for backups
Permissions: Standard user account (admin elevation on demand)
Runtime: UCRT (recommended) or MSVCRT (legacy systems)

📋 Supported APIs (Default)

WINHTTP → EXHTTP
WININET → EXINET
WS2_32 → EXWS2
SENSAPI → EXSENS
IPHLPAPI → EXIPHL
URLMON → EXURLM
NETAPI32 → EXNETAPI
WSOCK32 → EXWS
WINTRUST → EXTRUST

🛡️ Safety Features

Automatic Backups: All originals saved to backup/ folder
Permission Management: Auto-handles Windows file permissions
Progress Tracking: Real-time logging of all operations
Batch Processing: Multi-threaded operations keep UI responsive
Checksum Recalculation: Valid PE files after patching

⚠️ Important Notes

Administrator Rights: File modifications may require elevation
Runtime Selection: Choose UCRT for modern systems, MSVCRT for legacy
Architecture Matching: Use correct DLL version (x32/x64/arm64)
Backup Your Files: Always test on copies first
Virtual Machines: Use VMs for initial testing
System Restore Points: Create restore points before patching
Signature Validation: Patching may invalidate digital signatures

🐛 Troubleshooting

Problem	Solution
"Permission Denied"	Run PowerShell as Administrator; check UAC settings
Application won't start	Ensure Windows 10+ or compatible runtime installed
DLL not found error	Verify correct architecture and runtime in API/ folder
Files don't get patched	Check if target DLLs are present in config.py
UI frozen	Application is processing; wait for progress bar to complete
Runtime mismatch	Use UCRT for Windows 10/11; MSVCRT for older systems

🔄 Restoring Original Files

If issues occur:

From Backup: Restore from backup/ folder created during patching
Manual Restore: Replace patched file with original
System Restore: Use Windows System Restore to previous point
Clean Installation: Reinstall affected application
Remove DLLs: Delete installed DLLs from System32/SysWOW64 if needed

📞 Support

Issues: Report bugs on GitHub Issues
Feature Requests: Submit with [FEATURE] tag
Language Support: Available in upcoming release

📜 License

GNU General Public License v3.0 (GPL-3.0)

This software is free to use, modify, and distribute under GPL terms. See LICENSE file for details.

🔗 Additional Resources

📝 Version History

v1.0 (Current Release)

Initial release
IAT and Hex patching support
Batch file processing
Real-time logging
Ukrainian interface
Pre-compiled DLLs for x32, x64, ARM64
UCRT and MSVCRT runtime options

v1.1 (Coming Soon)

Multilingual support (English, Ukrainian, others)
Enhanced UI/UX improvements
Additional API definitions

Status: Stable Release | Updated: 2025 | Support: Active

For the latest version and updates, visit the GitHub repository.

🔧 Automated Installation (Coming Soon)

An INNO Setup installer for x86-64 systems is planned for users who prefer automated installation. This will handle:

Automatic file extraction to Program Files
One-click DLL installation (with runtime selection)
System PATH configuration
Shortcut creation
Uninstall support

Check back for the automated installer release if manual installation feels tedious.

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PE API Replacer - Release Installation Guide

📦 What's Included

Package Contents

🚀 Quick Start

Windows

macOS / Linux

📁 Installing Replacement Libraries (Optional)

Selecting the Right Runtime

Installation by Architecture

For 32-bit Applications (SysWOW64)

For 64-bit Applications (System32)

For ARM64 Windows Devices

🌍 Language Support

Current Release (v1.0)

Multilingual Release (Coming Soon)

⚙️ Configuration

For Advanced Users

🔧 System Requirements

📋 Supported APIs (Default)

🛡️ Safety Features

⚠️ Important Notes

🐛 Troubleshooting

🔄 Restoring Original Files

📞 Support

📜 License

🔗 Additional Resources

📝 Version History

v1.0 (Current Release)

v1.1 (Coming Soon)

🔧 Automated Installation (Coming Soon)

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