Hi Andreas,
Thanks for using Syncfusion products,
We have Upload box control with Upload progress in ASP Classic platform which may suits your requirement. So we suggest you to use ASP.Net(Classic ) Uploadbox and UploadProgress control Instead of using ProgressBar for the fileupload notification separately to achieve your scenario.
Please have a look on Online demo sample for the uploadbox with uploadprogress control sample in below link:
http://asp.syncfusion.com/demos/ui/tools/Upload/ProgressAndFilters/cs/ProgressAndFilters.aspx
Please refer the below UG-Documentation for the Uploadbox and UploadProgress control:
http://help.syncfusion.com/ug/asp.net/documents/uploadboxanduploadpr.htm
We have prepared the ASP.Net(Classic ) Uploadbox and UploadProgress control sample and it’s available in the below link:
http://www.syncfusion.com/downloads/support/directtrac/118465/SampleUploadbox-1140097941.zip
Please let us know if you have further queries.
Regards,
Muralishankar