There are two servers, firewalls for them are all disabled
[u]Server A (Website Server):</u>
Windows Server 2003
IIS 6.0

[u]Server B (SQL Server):</u>
Windows Server 2003
MS SQLServer 8.00.194

I try to connect the Server B through an ASP page on Server A, but got the error "Microsoft OLE DB Provider for SQL Server error '80004005'
[DBNETLIB][ConnectionOpen (Connect()).]SQL Server does not exist or access denied. "

My code as below:
    Set Conn = Server.CreateObject ("ADODB.Connection")
    Conn.Mode = adModeReadWrite
    Conn.ConnectionString = "Provider = Sqloledb; User ID = username; Password = mypwd; Initial Catalog = OfficeStuff; Data Source = ServerIP;"
    Conn.Open

Any idea?

Do you have the credentials or permissions to logon to that computer with the specified account?

thanks for help. problem is solved by updating SQL server to SP4. but another problem comes, I tested my code on my own web server in home. I need to upload the website into a virtual webhosting. the tech support told me "you can connect to another MySQL
server from our hosting accounts. Applications that need to make
outgoing connections will need to be made "proxy aware". This will
require additional coding to varying degrees, depending on the
application. The ip of the proxy server is 64.202.165.130 and
connections will be made on port 3128. Http connections are completely
transparent for making only port 80 connections. Please contact us if
you have any further questions."

what does it mean? how should I write the connection string? Many thanks!

A common problem that happens and gives similar errors to the one your getting is the versions of mdac between them are different. Either through a different service pack, or an application installed on one not installed on the other upgraded the mdac version. Try to get a recent mdac, apply them to both boxes and then insure the installed dll's are the same versions. Then see if you still have the same problem.