Is it wise or foolish to have other anti virus software running, ie. Microsoft Security Essentials, Malwarebytes, when you are running Avast 7.0 Security. Is this just a waste of resources?
Not a problem running MalwareBytes with avast, but I wouldn’t run Microsoft Security Essentials.
Having two resident anti-virus scanners installed is one too many and not recommended as rather than provide twice the protection it can cause conflicts that could leave you more vulnerable.
It’s problematic to run more than once full antimalware tool. I mean, as resident.
avast! could conflict, sooner or later, with MSE.
avast! is compatible with MBAM (free and Pro) right now.
MBAM is definitely safe. This might help http://www.bleepingcomputer.com/forums/topic260844.html/page__p__1441638#entry1441638 
If you feel the need to run more than one AV program on your computer you should use avast! along with any number of “On Demand” AV programs. However, as mentioned above stay away from running two real-time AV programs simultaneously.
Some “On Demand” anti-virus programs that you might want to consider are
- Bit Defender Monthly Top 100 which scans for the top 100 malware programs and is updated monthly.
- Dr. Web Cureit
- Norman Malware Cleaner
- Hitman Pro
- ESET On-line Scanner
- Bit Defender add-on for Firefox
- Housecall Launcher
- McAfee Stinger
- Microsoft Support Emergency Response Tool
- Microsoft Windows Defender Offline Wizard Package.
There are probably some more but those are the ones that I am familiar with and have used from time to time. You can of course also use anti-spyware programs like Malwarebytes Pro and SuperAntiSpyware Pro in real-time.