BUG #7526: An error occured executing the Microsoft VC++ runtime installer

The following bug has been logged on the website:

Bug reference:      7526
Logged by:          Dan
Email address:      s3n_dan@yahoo.com
PostgreSQL version: 8.4.7
Operating system:   Windows Vista Home Premium
Description:        =


Please help me with this error, i tried everything i found for this issue
but didn't work for me ,

If i try to install the latest version 9.1.5 i will get another error :
unable to write inside TEMP environment variable path


you can find below the log file for 8.4.7 version:

Log started 09/09/12 at 13:29:37
Preferred installation mode : unattended
Trying to init installer in mode unattended
Mode unattended successfully initialized
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Data
Directory. Setting variable iDataDirectory to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Base
Directory. Setting variable iBaseDirectory to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Service
ID. Setting variable iServiceName to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Service
Account. Setting variable iServiceAccount to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Super
User. Setting variable iSuperuser to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4
Branding. Setting variable iBranding to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4 Version.
Setting variable brandingVer to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4
Shortcuts. Setting variable iShortcut to empty value
Could not find registry key
HKEY_LOCAL_MACHINE\SOFTWARE\PostgreSQL\Installations\postgresql-8.4
DisableStackBuilder. Setting variable iDisableStackBuilder to empty value
[13:29:39] Existing base directory: =

[13:29:39] Existing data directory: =

[13:29:39] Using branding: PostgreSQL 8.4
[13:29:39] Using Super User: postgres and Service Account: postgres
[13:29:39] Using Service Name: postgresql-8.4
Executing cscript //NoLogo
"C:\Users\Dan\AppData\Local\Temp\postgresql_installer\installruntimes.vbs"
"C:\Users\Dan\AppData\Local\Temp\postgresql_installer\vcredist_x86.exe"
Script exit code: 1

Script output:
 CScript Error: Can't find script engine "VBScript" for script
"C:\Users\Dan\AppData\Local\Temp\postgresql_installer\installruntimes.vbs".

Script stderr:
 Program ended with an error exit code

An error occured executing the Microsoft VC++ runtime installer.
An error occured executing the Microsoft VC++ runtime installer.

Thank you in advance

Dan