I found a two year three PC license for BDIS on Amazon for $19.00 or thereabouts so I decided to purchase it and replace BD AV Free on my W7-SP1 computer with BDIS. I have a had a license for BD W8 Security for over a year and have it installed on my W8.1 computers. Works great.
Anyway the instllation of BDIS was a bit of pain to say the least. After uninstalling BD AV Free and MBAM 2.0.0.0504 (2.0 Beta 3) I set about installing BDIS. I then reinstalled MBAM 2.0.0.0504. Along the way I had to manually allow BDIS in the Windows 7 firefwall and set up the malware file scanning exceptions in both BDIS and MBAM 2.0.0.0504. Still BDIS was not working correctly. Twice more I uninstalled MBAM 2.0.0.0504 and ran two repairs of BDIS along with rebooting a couple of times.
To make a long story short after installing BDIS, running repair twice, uninstalling and reinstalling MBAM 2.0.0.0504 I can't remember how many times and rebooting maybe a dozen times both appear to now be working fine together.
Getting BDIS updates to work properly were particularly troublesome and even required a new Microsoft program to be downloaded; i.e., one that had not previously been installed on my W7 computer. Sorry I can't remember which Windows program it was. BDIS said I needed to install the update and I did however after doing so I had to again uninstall MBAM 2.0.0.0504 and reinstall it.
My suggestion is don't try and install BDIS and MBAM 2.0.0.0504 (MBAM 2.0 Beta 3) together unless you are at least a semi advanced user and have lots of patience.
BD AV Free and MBAM 2.0.0.0504 had no problems whatsoever co-existing.
How much of the problems I had getting both to work together were due to BDIS or MBAM Beta 3 I have no idea I did do a System Scan with BDIS and it picked up what appeared to be a PUP and quarantined it. BD AV Free did not do anything with it. The PUP was found in a free version of a software I am using. I also have a license for three computers of that program and it was not present in that programs folder path. It is possible that BD W8 Security had found it and deleted it but my guess after doing some research on the Net is that file is only present in the free version and could be there in case you purcahase the product and enter a license. Before deleting the file I checked BDIS quarantine and it said the file had not been uploaded for reveiw by BD. Why it was not uploaded I do not know. It could have been the W7 firewall. Anyway I will keep an eye on quarantined files going forward and if they don't upload for verification of a possible FP I will create a ticket.
cheers.
Hopefully BDIS and MBAM 2.0 Betas and RTM will conintue to work fine together as they appear to be now doing. 
