I can't find direct info with a quick search, but I'm pretty sure the answer is No, the rule of thumb is you must have only 1 product of each type running real time cover, so 1 firewall (this includes windows own, but excludes routers), 1 anti virus and 1 anti spyware, running more than 1 of each can cause conflict, there are rare exception(s), ThreatFire can be run alongside an active anti virus, but it's the only one I know of personally, there may be others I'm not aware of, but rule of thumb for real time cover is 1 of each type running at the same time.
You can however still use other scanners as standalone protection, but you must remember to disable\pause real time cover from your other source before running anything else, including online scans, hope this helps.
