Were you installing the client software or the server software? I'm going to assume you were installing the client software.
You do not indicate why your installation failed. The mostly likely cause of the failure is the User Access Control (UAC) feature of Vista. I think the readme file alluded to this, but it's been a while since I read it. I also think the Quality Center is only officially supported on Vista if you use the QCExplorer addin. Anyway... try this.
1) Turn off UAC. This will require a reboot.
2) Execute the install of the Quality Center Client-Side files from the QC addons page to ensure all the ActiveX controls get properly installed.
3) You can try to access the site through IE7 on Vista, and it may initially work. But since HP said to use QCExplorer, it's possible there is a less obvious reason. Download and run QCExplorer to access Quality Center and verify you can login.
4) Turn UAC back on and reboot.
This is the typical scenario for use on Vista. If you continue to have errors, try being more descriptive about the exact problem. Hope this helps!
You have to run the server side of Quality Center on a server-class operating system. Running on Vista is not an option.
If you are doing this for testing purposes, what I typically do is install a product like VMWare Workstation (or the free version VMWare Server) that allows you to create virtual machines on your Vista workstation. Then you can install the proper server OS inside that virtual machine and use it to load/launch your Quality Center software.
Mind you... that would be for a testing scenario only. If you want to use this production, get a machine setup with the proper OS.
"QC 9.2 does not support Vista" is not entirely correct.
Boyd's posts are important ones to understand.
The QC application cannot be installed on Vista, as it requires a server-class OS.
The QC CLIENT can be used in Vista. You need to be clear about what it is your installing and what the problem is.
The QC web client operates in a browser, and the browser bundled with Vista is IE7.
QC9.2 does work with IE7.
If you're running Vista you simply need to get around UAC to download/install/register/use the dll's that are pulled when you first log in (or first log in after a patch/upgrade)
There are two ways to do this:
1. Disable UAC
2. right click the IE icon and choose "Run as Administrator"
I use method #2, and I'm using QC9.0 and Qc9.2 with no issues.
For your DB connection issue, talk to your DBA, and find out what method is used in tnsnames.ora to identify the server. You need to use the same method - it could be the IP address, or it could be the server name.