Bill,

Yes, that Patch 28 has a quirk with this. It has some issues with some of the previous patches.

The best thing to do is to:

BACKUP your back-end DB,

BACKUP your repository folders

Make a backup of your current siteadmin.xml file from your (QC install path)Application20qcbin.warWeb-INF -- this file has various settings you may need.

Then, in Windows Control Panel Add-Remove Programs (or similar for your flavor of Windows), check the Updates checkbox near the top and scroll down to Quality Center 10 in the list of installed programs.
You should see all of your previous QC patches listed.

Uninstall each patch, going backward from the most recent. DO NOT uninstall QC10.
When you get to the UN-Patched QC10, then install Patch 28.
This may require some manual intervention starting and stopping the QC Service or a few retries to get the patch uninstallers to do it.

This may take a few hours of QC downtime, depending on how many patches you have installed.

Good Luck, and remember, if you feel this is over your head, ask for Tech Support to help you.

We started uninstalling the older patches and now when we try to go into Site Admin to check our unpatched QC with Internet Explorer, we get an unsupported version error.

Bill,

This happens because your IE version is much newer than what was supported with unpatched QC.
You really don't need to do it, but you can do a quick check of the patch level by going to this URL (replace with your server address).
http://yourserver:8080/qcbin/About.htm

Keep going, now install Patch 28.