1. uninstall sql server2005,
2. uninstaill vs2005
3. uninstaill .net framework2.0
4. install sp3 for sql2000
5. install report server for sql 2000 xp

But I met the problem error info at the end of the installing:

Then I found the post from http://www.sqlreportingservices.net/Ask/4743.aspx

My problem is solved; I think you only need to change the installation path of RS during the setup, but the following are the steps I follow:

 1. Uninstall RS
 2. Clean all signs of RS in the registry, the service and components
     Delete in the registry the entries in 
       HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\RS Rep..
    Delete the service using the command prompt
      sc delete ReportServer
   Delete the components in Component Services in the control panel Administrative Tools in the COM+ Applications for the ISS part of RS.
 3. Install RS in a different path
    I install RS in C:\Program Files\Microsoft SQL ServerRS
   Also i rename the services in the setup to MSReportService, MSReports for the
   IIS part.

 I have Windows XP with all in one box; I use a domain account for the services
 and for the SQL login.