Download the HP run test set scheduler from your support organization or HP, this will allow you to execute all of the test sets under a given folder in the quality center test lab. Unzip the test set scheduler and place it directly under the C: drive on the QTP/UFT machine then you will need to create a batch file to execute the tests using the scheduler. Once you have created a batch file you can then add the batch file to the windows scheduler to be run at certain times making this process automated. A few things to make sure of, make sure that the test sets in the folder only contain UFT automated tests, sometimes I have seen manual tests in the folder affect how this works. Also if it is not working, make sure that there are not any spaces in the folder path to the folder, if there are spaces in the folder path, edit the names of the folders in the path to make sure they do not have spaces. Here is an example of what my batch file would look like:

cd C:RunTestSetScheduler_ALM_v2.5RunTestSetScheduler_ALMRunTestSetScheduler_ALMbinRelease
RunTestSetscheduler_ALM.exe /s:http://jyalmserv:8080/qcbin /n:default /d:project5 /u:qcadmin /p:qcadmin /f:Roottestfoldername

In the above example I am logging into the qc domain and project and telling the scheduler to run all of the test sets in the ''Roottestfoldername'' folder

Do you have any particular link for downloading the HP run test set scheduler ?