I decided to install sql server 2008 and all went well suprisingly
But after trying to connect to Reporting Services 2008 and tried running Reporting Services Configuration Manager
I get error :
"No report servers were found. Details: Invalid namespace"
Below is a solution i was from one of the MSDN posts:
Steps to modify the ReportingServices.MOF file to fix this issue:
1. Locate the existing MOF file (example: %ProgamFiles%\Microsoft SQL Server\MSRS10.SQL2008\Reporting Services\ReportServer\bin\reportingservices.mof would be the default location for a Reporting Services instance named SQL2008).
2. Copy this reportingservices.mof to reportingservicesalt.mof (or some other unique name).
3. Notepad reportingservicealt.mof
4. Choose edit->replace…
5. In the dialog, in the Find What: text box enter the modified instance name (for an RS instance named SQL2008, the modified instance name is RS_SQL2008), in the Replace with: text box enter the instance name unmodified (so for an RS instance named SQL2008, just enter SQL2008).
6. Press the Replace All button.
7. Save and close notepad.
8. From a command window at the same location as the results of step 1, type MOFCOMP REPORTINSERVICESALT.MOF (or whatever the name from step 2 was).
Now the configuration tool should work with the following exception, if the RS instance name contains an underscore (_), a dollar sign ($) or a hash (#), then step 8 will fail and the user will need to re-install the Reporting Services instance with a name that does not include any of these three characters.
There is also a detailed solution here and it works.
Enjoy