Is it reasonable or advisable to run two different "real-time protection" apps simultaneously (i.e., anti-virus and anti-spyware/malware)?
My experience with a few of these is, "generally, yes." (But absolutely not two of the same type of application.)
Some applications have some issues with some others...there are AV's around that are a bit notorious for not "playing well" with other applications. Some combinations seem to give a greater performance hit than others. It can be complex, every computer configuration is different, the best bet is probably to try out the different combinations you want to try. It can be a good idea to google your proposed combo first, for example (refine the search term as you see fit.) http://www.google.co.nz/search?hl=en&q...earch&meta=