"Could not create an environment: OCIEnvCreate returned -1. "

[Big Charles]

Hello,

I have an ASP.NET 1.1 web application running in a Windows Server 2003.
Connects to Oracle 10g through Oracle 10g Client. Data base in another
server.
But I can't connect web application to Database. Web Site is hosted in
IIS 6.0 and I try to run from there.
I gave already assigned rights:
- Read & Execute
- List Folder Contents
- Read
to users ASP.NET and NETWORK SERVICE to folder
C:\Oracle\Product\10.1.0\ and reboot several times the PC, but allways
I get the error: "Could not create an environment: OCIEnvCreate
returned -1. "
I login as administrator of the Windows 2003

Any help would be great. Thank you !