Photoshop
You need to have a valid setup.iss file for a silent Photoshop installation.
First make sure you don't have any setup.iss file in your %WINDIR% folder (to be sure the one we create is really made by us). If there is any, delete or rename it - it is not used by your system.
Next, launch the installer with setup.exe /r and go through the whole installation.
After it's done, you will have a new setup.iss file in the %WINDIR% folder. Copy it to the Photoshop setup directory (make sure you didn't have one there before, if you did, rename it).
The uninstaller needs a similar operation with a /r switch.
<package
id="photoshop801"
name="Photoshop CS 8.0.1"
revision="1"
reboot="true"
priority="0">
<check type="uninstall" condition="exists" path="Adobe Photoshop CS" />
<install cmd="%SOFTWARE%\Photoshop\setup.exe -s -f2%TEMP%\photoshop.log" />
<remove cmd="%SOFTWARE%\Photoshop\uninstall\photoshop-uninstall.bat" />
</package>
The photoshop-uninstall.bat will look like this (in one line):
"%PROGRAMFILES%\InstallShield Installation Information\{EFB21DE7-8C19-4A88-BB28-A766E16493BC}\setup.exe" -s -f1"%SOFTWARE%\photoshop\Uninstall\photoshop-uninstall.iss" -f2"%TEMP%\photoshop-uninstall.log"
Here's another way if you have a different installer:
<package id="photoshopcs2" name="Adobe Photoshop CS2" revision="1" priority="0" reboot="false">
<check type="uninstall" condition="exists" path="Adobe Photoshop CS2" />
<install cmd='reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{236BB7C4-4419-42FD-0407-1E257A25E34D}" /v EPIC_REGS_TYPE /t REG_DWORD /d 0x00000004 /f' />
<install cmd='reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{236BB7C4-4419-42FD-0407-1E257A25E34D}" /v EPIC_REGS_STATE /t REG_DWORD /d 0x00000002 /f' />
<install cmd='reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{236BB7C4-4419-42FD-0407-1E257A25E34D}" /v EPIC_REGS_LANG /t REG_DWORD /d 0x00000002 /f' />
<install cmd='reg add "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{236BB7C4-4419-42FD-0407-1E257A25E34D}" /v EPIC_REGS_COUNT /t REG_DWORD /d 0x00000000 /f' />
<install cmd='msiexec /l* c:\netinst\logs\photoshop.log /qn /i "%SOFTWARE%\photoshop-cs2\Adobe(R) Photoshop(R) CS2\Adobe Photoshop CS2.msi"' />
<remove cmd='msiexec /qn /l* c:\netinst\logs\UNphotoshop.log /x {236BB7C4-4419-42FD-1E257A25E34D}' />
</package>