Legacy Database Platforms:
- SQL Server 7.0/2000
- Oracle 8i/9i
- Sybase SQL Server
- Informix Dynamic Server
- Microsoft Access 97/2000
- dBase/Clipper applications
- Paradox databases

@echo off
:: Legacy Application Discovery Tool
echo Legacy Application Assessment > app_assessment.txt
echo ========================== >> app_assessment.txt
echo Assessment Date: %DATE% %TIME% >> app_assessment.txt
echo. >> app_assessment.txt

:: List installed applications
echo Installed Applications: >> app_assessment.txt
echo ---------------------- >> app_assessment.txt
reg query HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall /s | find "DisplayName" >> app_assessment.txt

:: Check for 16-bit applications
echo. >> app_assessment.txt
echo 16-bit Applications: >> app_assessment.txt
echo ------------------- >> app_assessment.txt
dir C:\*.exe /s /b | findstr /i "dos win16" >> app_assessment.txt

:: Database applications
echo. >> app_assessment.txt
echo Database Services: >> app_assessment.txt
echo ----------------- >> app_assessment.txt
sc query type= service | find "SQL" >> app_assessment.txt
sc query type= service | find "Oracle" >> app_assessment.txt

:: IIS applications
echo. >> app_assessment.txt
echo IIS Applications: >> app_assessment.txt
echo ---------------- >> app_assessment.txt
cscript C:\Inetpub\AdminScripts\adsutil.vbs ENUM /P W3SVC >> app_assessment.txt

:: COM components
echo. >> app_assessment.txt
echo Registered COM Components: >> app_assessment.txt
echo ------------------------- >> app_assessment.txt
reg query HKCR\CLSID /s | find "InprocServer32" | find ".dll" >> app_assessment.txt

' Application Dependency Checker
' Save as check_dependencies.vbs

Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objShell = CreateObject("WScript.Shell")

Function CheckAppDependencies(strExePath)
    WScript.Echo "Checking: " & strExePath

    ' Check file version
    Set objFile = objFSO.GetFile(strExePath)
    WScript.Echo "  File Date: " & objFile.DateLastModified
    WScript.Echo "  File Size: " & objFile.Size

    ' Check for DLL dependencies using depends.exe
    strCommand = "depends.exe /c /ot:dependencies.txt """ & strExePath & """"
    objShell.Run strCommand, 0, True

    ' Parse results
    If objFSO.FileExists("dependencies.txt") Then
        Set objTextFile = objFSO.OpenTextFile("dependencies.txt", 1)
        strText = objTextFile.ReadAll
        objTextFile.Close
        WScript.Echo "  Dependencies found - see dependencies.txt"
    End If
End Function

' Example usage
CheckAppDependencies("C:\Program Files\LegacyApp\app.exe")

:: Windows 2000 Application Compatibility Registry Settings
:: Save as app_compat.reg

Windows Registry Editor Version 5.00

; Enable compatibility mode for specific applications
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers]
"C:\\LegacyApp\\app.exe"="WIN98"
"C:\\OldApp\\old.exe"="WIN95"

; Disable DEP for legacy applications
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\NoExecute]
"C:\\LegacyApp\\app.exe"=dword:00000001

; Force single processor affinity
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\app.exe]
"AffinityMask"=dword:00000001

:: Install ACT components for Windows 2000
:: Note: Use older versions compatible with Win2000

1. Application Verifier 3.0
2. Compatibility Administrator
3. Internet Explorer Compatibility Test Tool

:: Create compatibility database
compatadmin.exe

:: Apply compatibility fixes
sdbinst.exe custom_app_fixes.sdb

:: Configure NT Virtual DOS Machine for 16-bit apps
:: Edit C:\WINNT\System32\CONFIG.NT

dos=high, umb
device=C:\WINNT\System32\himem.sys
files=40
buffers=20
stacks=9,256
shell=C:\WINNT\System32\command.com /e:2048 /p

:: AUTOEXEC.NT configuration
@echo off
SET PATH=C:\WINNT\System32;C:\WINNT;C:\DOS
SET TEMP=C:\TEMP
SET TMP=C:\TEMP
lh C:\WINNT\System32\mscdexnt.exe
lh C:\WINNT\System32\redir
lh C:\WINNT\System32\dosx

:: DOS application compatibility settings

:: Set memory configuration
setver app.exe 6.22
mem /c > memory_config.txt

:: Configure expanded memory
device=C:\WINNT\System32\emm386.exe 2048 RAM

:: Environment variables for DOS apps
SET DIRCMD=/OGN /4
SET COPYCMD=/Y

; WIN.INI modifications for 16-bit Windows apps
[windows]
ScreenSaveActive=0
Programs=com exe bat pif cmd
Documents=
device=
NullPort=None

[Desktop]
Pattern=(None)
TileWallpaper=0
WallpaperStyle=0

[compatibility]
NTVDM=0x400

-- Legacy SQL Server maintenance procedures

-- Check database compatibility level
SELECT name, compatibility_level 
FROM sys.databases
WHERE compatibility_level < 80

-- Set compatibility for legacy apps
ALTER DATABASE LegacyDB SET COMPATIBILITY_LEVEL = 70

-- Create maintenance procedures
CREATE PROCEDURE sp_LegacyMaintenance
AS
BEGIN
    -- Rebuild indexes
    DBCC DBREINDEX('LegacyTable', '', 80)

    -- Update statistics
    UPDATE STATISTICS LegacyTable WITH FULLSCAN

    -- Check consistency
    DBCC CHECKDB('LegacyDB') WITH NO_INFOMSGS
END

-- Schedule maintenance
EXEC sp_add_job @job_name = 'Legacy DB Maintenance'
EXEC sp_add_jobstep @job_name = 'Legacy DB Maintenance',
    @step_name = 'Run Maintenance',
    @command = 'EXEC sp_LegacyMaintenance'

' Access 97/2000 database maintenance
Dim objAccess, strDBPath

strDBPath = "C:\LegacyApp\data.mdb"

' Compact and repair
Set objAccess = CreateObject("Access.Application")
objAccess.CompactRepair strDBPath, strDBPath & ".tmp"
objFSO.DeleteFile strDBPath
objFSO.MoveFile strDBPath & ".tmp", strDBPath

' Convert to newer format if needed
objAccess.ConvertDatabase strDBPath, "C:\LegacyApp\data_2000.mdb", acFormat2000

:: Create symbolic links for hard-coded paths
:: Using junction points in Windows 2000

:: Download junction.exe from Sysinternals
junction "C:\OldPath" "D:\NewPath"

:: For network paths, use subst
subst X: "\\server\legacy\app"

:: Make persistent across reboots
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\DOS Devices" /v X: /t REG_SZ /d "\??\UNC\server\legacy\app" /f

:: Manage DLL conflicts for legacy applications

:: 1. Use application-specific folders
md "C:\LegacyApp\System32"
copy "C:\WINNT\System32\legacy.dll" "C:\LegacyApp\System32\"

:: 2. Register private DLLs
regsvr32 /s "C:\LegacyApp\Components\custom.ocx"

:: 3. Create .local files for DLL redirection
echo. > "C:\LegacyApp\app.exe.local"

:: 4. Set DLL search order
:: Create app.exe.manifest for side-by-side assembly

:: Redirect registry access for legacy apps
:: Using RegEdit and custom scripts

:: Export legacy settings
reg export "HKLM\SOFTWARE\LegacyApp" legacy_settings.reg

:: Import to user hive if needed
reg import legacy_settings.reg /reg:64

:: Monitor registry access
regmon.exe /f "LegacyApp" > registry_access.log

:: Run legacy applications in isolated environment

:: 1. Create dedicated user account
net user LegacyAppUser ComplexP@ssw0rd /add
net localgroup "Power Users" LegacyAppUser /add

:: 2. Set process priority and affinity
start /low /affinity 1 "C:\LegacyApp\app.exe"

:: 3. Limit resource usage with Windows 2000 Resource Kit
cpustres.exe /limit:50 /process:app.exe

:: Isolate legacy application network access

:: Configure Windows Firewall (if available via SP)
netsh firewall set service type=custom name="LegacyApp" mode=enable protocol=tcp port=1433 scope=subnet

:: Use IPSec policies for additional control
netsh ipsec static add policy name="LegacyAppPolicy"
netsh ipsec static add filteraction name="Block" action=block

:: Create isolated file system for legacy apps

:: Set NTFS permissions
cacls "C:\LegacyApp" /E /G LegacyAppUser:F
cacls "C:\LegacyApp" /E /R Everyone

:: Enable auditing
auditpol /set /subcategory:"File System" /success:enable /failure:enable

:: Create separate temp directory
md "C:\LegacyApp\Temp"
setx TEMP "C:\LegacyApp\Temp" /m
setx TMP "C:\LegacyApp\Temp" /m

<!-- Application virtualization wrapper config -->
<VirtualApp>
    <Name>LegacyApplication</Name>
    <Executable>C:\LegacyApp\app.exe</Executable>
    <WorkingDirectory>C:\LegacyApp</WorkingDirectory>

    <FileSystem>
        <Redirect>
            <Source>C:\WINNT\System32\legacy.dll</Source>
            <Target>C:\LegacyApp\System32\legacy.dll</Target>
        </Redirect>
    </FileSystem>

    <Registry>
        <Redirect>
            <Source>HKLM\SOFTWARE\LegacyApp</Source>
            <Target>HKCU\SOFTWARE\LegacyApp_Virtual</Target>
        </Redirect>
    </Registry>

    <Environment>
        <Variable name="PATH" value="C:\LegacyApp;%PATH%" />
        <Variable name="TEMP" value="C:\LegacyApp\Temp" />
    </Environment>
</VirtualApp>

// Simple API wrapper for legacy applications
// Compile with Visual C++ 6.0 for Windows 2000

#include <windows.h>

// Wrap newer API calls for legacy apps
extern "C" __declspec(dllexport) 
BOOL WINAPI Legacy_CreateProcess(
    LPCTSTR lpApplicationName,
    LPTSTR lpCommandLine,
    LPSECURITY_ATTRIBUTES lpProcessAttributes,
    LPSECURITY_ATTRIBUTES lpThreadAttributes,
    BOOL bInheritHandles,
    DWORD dwCreationFlags,
    LPVOID lpEnvironment,
    LPCTSTR lpCurrentDirectory,
    LPSTARTUPINFO lpStartupInfo,
    LPPROCESS_INFORMATION lpProcessInformation)
{
    // Add compatibility fixes
    dwCreationFlags |= CREATE_DEFAULT_ERROR_MODE;

    // Call original API
    return CreateProcess(
        lpApplicationName,
        lpCommandLine,
        lpProcessAttributes,
        lpThreadAttributes,
        bInheritHandles,
        dwCreationFlags,
        lpEnvironment,
        lpCurrentDirectory,
        lpStartupInfo,
        lpProcessInformation);
}

START
│
├─ Is source code available?
│  ├─ YES → Can it be recompiled?
│  │  ├─ YES → Recompile for modern OS
│  │  └─ NO → Refactor code
│  └─ NO → Is vendor still in business?
│     ├─ YES → Request updated version
│     └─ NO → Find alternative solution
│
├─ Is application critical?
│  ├─ YES → Prioritize migration/replacement
│  └─ NO → Consider retirement
│
└─ Can application run in VM?
   ├─ YES → Virtualize as interim solution
   └─ NO → Immediate replacement required

Legacy Application Alternatives:

16-bit Applications:
  - DOSBox: DOS emulation
  - vDos: Enhanced DOS emulator
  - NTVDM alternatives

Database Applications:
  - SQL Server Express: Free SQL Server
  - PostgreSQL: Open source alternative
  - MariaDB: MySQL compatible

Development Platforms:
  - .NET Framework: VB6 migration path
  - Visual Studio: Modern development
  - Cross-platform alternatives

Business Applications:
  - Modern ERP systems
  - Cloud-based solutions
  - Open source alternatives