After you upgrade from Joomla! 1.5 to 1.7, the old module of Joomla! 1.5 can not be used anymore and you have to reinstall the module is compatible with the new version of Joomla. But if you can not find the module compatible with Joomla! 1.7, in this case, you can try converting them to be used with Joomla! 1.7

Convert a simple module for Joomla! 1.5 to 1.7

1. Login to Administrator of Joomla! 1.7, then install the old module.

2. Browse to the module's folder. They are usually located in the folder modules/mod_modulename.

3. Open the xml file of the module. This file is named like the name of the folder (eg mod_modulename.xml).

4. Change the parameters of the old version for compatibility with new version:

Find:

<install type="module" version="1.5"> 

Replace with:

<extension type="module" version="1.7" client="site" method="upgrade">

Find:

<params>

Replace with:

<config>
   <fields name="params">
      <fieldset name="basic">

Find:

<params group="advanced">

Replace with:

<fieldset name="advanced">

Find:

<param name="module_parameter" ... >
</param>

Replace with:

<field name="module_parameter" ...>
</field>

Find:

<param name="cache" type="list" default="0" label="Caching" description="Select whether to cache the content of this module">
   <option value="1">Use global</option>
   <option value="0">No caching</option>
</param>
<param name="cache_time" type="text" default="15" label="Cache Time" description="The time in minutes before the module is re-cached." />

Replace with:

<field name="layout" type="modulelayout" label="JFIELD_ALT_LAYOUT_LABEL" description="JFIELD_ALT_MODULE_LAYOUT_DESC" /> 
<field name="moduleclass_sfx" type="text" label="COM_MODULES_FIELD_MODULECLASS_SFX_LABEL" description="COM_MODULES_FIELD_MODULECLASS_SFX_DESC" />
<field name="cache" type="list" default="1" label="COM_MODULES_FIELD_CACHING_LABEL" description="COM_MODULES_FIELD_CACHING_DESC">
 <option value="1">JGLOBAL_USE_GLOBAL</option>
 <option value="0">COM_MODULES_FIELD_VALUE_NOCACHING</option>
</field>
<field name="cache_time" type="text" default="900" label="COM_MODULES_FIELD_CACHE_TIME_LABEL" description="COM_MODULES_FIELD_CACHE_TIME_DESC" />

Find:

</params>

Replace with:

</fieldset>

Find:

</install>

Replace with:

      </fields>
   </config>
</extension>

Sample

Joomla! 1.5 module xml

<?xml version="1.0" encoding="utf-8"?>
<install type="module" version="1.5.0">
   <name></name>
   <author></author>
   <creationDate></creationDate>
   <copyright></copyright>
   <license></license>
   <authorEmail></authorEmail>
   <authorUrl></authorUrl>
   <version></version>
   <description></description>
   <files>
      <filename module="mod_name">mod_name.php</filename>
      <filename>index.html</filename>
      <folder>tmpl</folder>
   </files>
   <params>
      <param name="moduleclass_sfx" type="text" default="" label="Module Class Suffix" description="PARAMMODULECLASSSUFFIX" />
      <param name="@spacer" type="spacer" default="" label="" description="" />
      <param name="module_parameter"></param>
   </params>
   <params group="advanced">
      <param name="cache" type="list" default="0" label="Caching" description="Select whether to cache the content of this module">
         <option value="1">Use global</option>
         <option value="0">No caching</option>
      </param>
      <param name="cache_time" type="text" default="15" label="Cache Time" description="The time in minutes before the module is re-cached." />
   </params>
</install>

Joomla! 1.7 module xml

<?xml version="1.0" encoding="utf-8"?>
<extension type="module" version="1.7" client="site" method="upgrade">
   <name></name>
   <author></author>
   <creationDate></creationDate>
   <copyright></copyright>
   <license></license>
   <authorEmail></authorEmail>
   <authorUrl></authorUrl>
   <version></version>
   <description></description>
   <files>
      <filename module="mod_name">mod_name.php</filename>
      <filename>index.html</filename>
      <folder>tmpl</folder>
   </files>
   <config>
      <fields name="params">
         <fieldset name="basic">
            <field name="module_parameter"></field>
         </fieldset>
         <fieldset name="advanced">
            <field name="layout" type="modulelayout" label="JFIELD_ALT_LAYOUT_LABEL" description="JFIELD_ALT_MODULE_LAYOUT_DESC" />
            <field name="moduleclass_sfx" type="text" label="COM_MODULES_FIELD_MODULECLASS_SFX_LABEL" description="COM_MODULES_FIELD_MODULECLASS_SFX_DESC" />
            <field name="cache" type="list" default="1" label="COM_MODULES_FIELD_CACHING_LABEL" description="COM_MODULES_FIELD_CACHING_DESC">
               <option value="1">JGLOBAL_USE_GLOBAL</option> 
               <option value="0">COM_MODULES_FIELD_VALUE_NOCACHING</option> 
            </field>
            <field name="cache_time" type="text" default="900" label="COM_MODULES_FIELD_CACHE_TIME_LABEL" description="COM_MODULES_FIELD_CACHE_TIME_DESC" />
         </fieldset>
      </fields>
   </config>
</extension>

This usually applies to cases where the module installed but does not displaythe parameter settings.