Looks like you didn't do a clean uninstall. I've seen this happen with upgrades, especially to SR6+ for some reason. If you don't have too many tasks defined, I would say (1) uninstall again, (2) remove the folders in C:\ProgramData\QlikTech (but make sure to backup the QVPR just in case); (3) remove the registry values in HKLM\Software\QlikTech and/or HCKU\Software\Qliktech; and (4) reinstall.
Vlad, I uninstalled and removed everything as you said. Then I installed v10 SR3. Everything seems to work, I can get to the QMC and QEMC and set all the various configurations however, when I try to go to the Access Point I get the “Internet Explorer cannot display the webpage” page. I installed without IIS. Is there some setting that I’m missing?
Open QEMC >> Services. Does QVWS have a green or red icon? If it's red: (a) is the service actually started? (b) are there any errors in the Windows Event Log? (c) Is the service account a local admin?