Note: This thread is not intended to explain how to use these programs.
EPC = Electronic Parts Catalog. It provides assistance in determining replacement parts and part numbers.
WIS = Workshop Information System. It contains detailed instructions on repair work.
ASRA = An electronic catalog for work units and flat rates (aka "book time" calculator).
EWA = Computer interface used to installing EPC/WIS/ASRA on your "standalone" PC
There are basically 3 options to use the EPC and WIS/ASRA. You can use the official online versions at the Mercedes website, download or buy full installers for your PC, or purchase a "pre-installed" version that runs in a virtual environment. Here is some basic info on the three options:
Option 1: Run the official, legal, MB-approved version at the Mercedes website
The US EPC is a free subscription for US residents, for USA data only. US residents can get worldwide data for $12 per year. A credit card is required even for the free subscription and it must have a USA billing address, or you will not be allowed to access the site. There is an equivalent European site for EU residents. The rest of the world is out of luck and will need to use one of the other two options below.
The advantage of using the online EPC is that it should always have the latest information available, and there are no concerns about installing programs from questionable sources with potential spyware or malware. Plus it's fully legal. Another nicety is that after selecting a main group, the online EPC will show you a thumbnail of all the subgroup diagrams, by default. The standalone EPC does not have this feature enabled by default, you have to manually turn this on in the options. Also, datacard access is enabled by default in the online EPC, again, this is not enabled by default in the standalone version.
The disadvantage is that you must have Internet access, a reasonably fast broadband connection, and decent hardware to run the Java app. Also - the WIS is NOT free online. MB charges $20/day, $100/week, $289/month, or $3098/year for WIS access!!! Another nuisance is that the programs cannot be left running on your PC indefinitely. If you leave them open overnight, they will not work the next morning, you have to close the program and re-launch it. This isn't a problem for the casual user, but for people who leave their EPC open 24x7 (like me), it's a dealbreaker. Which brings us to the next option.
Option 2: Buy a bootleg, pirated version from eBay or download via torrent sites
This had been the only option available before MB offered the official online versions. It comes on multiple dual-layer DVD's (or, multiple ISO images if you are into the torrent thing). You first have to install EWA (previously named EWA-net), then you use EWA to load the EPC and/or WIS/ASRA databases. Be careful when buying from eBay vendors, as they may sell EPC and WIS/ASRA separately, or together in a single package. The full installation requires somewhere around 50GB of hard drive space. The installation is slow, tedious, and generally a PITA. The seller may or may not have good technical support to help you get it installed & working. In rare cases, it may not work on a particular PC, and you will need to try installing on a different PC, or give up. The installation package can be very picky about the exact sequence, you will need to follow the instructions to the letter. After installation there is configuration required in the EWA interface, before you can launch the programs.
The advantages are speed, no cost, and no internet access required. And you don't need to renew an EPC subscription every year, or pay for worldwide EPC data access every year. This standalone EPC will be quicker than the online version, particularly if you have a slow internet connection where you live. And you can leave it running on your PC all the time, 24x7, with no problems. Also, there is no subscription charge for the WIS. We don't really need the WIS for the 500E anyway, but if you work on newer model Mercedes (late 1990's and up), the WIS is required. A major advantage for users outside the USA and Europe (i.e., Canada, Japan, Middle East) is that you're not limited by MB's stupid regional rules where they won't let you play online if you don't live in an "approved" country.
The disadvantage to the standalone installation is the slow, tedious, PITA installation. And if you download from torrent sites, you are at risk for malware/spyware. In rare cases it may not work on your PC at all, so it's good to have another PC available in case that happens. (You'll find out after installing EWA, but before installing EPC or WIS, if it's not gonna work.) Datacards and diagram preview are not enabled by default. It's a PITA to enable the datacards (as of this writing, none of the vendors are including instructions on how to do this).
Option 3: Buy a bootleg, pirated version from eBay, pre-intstalled in a virtual environment
This is a more recent offering. Any seller claiming their EPC/WIS runs on Mac OS or Linux, is selling a pre-installed version of EWA/EPC/WIS inside a virtual environment/container. The one I got from eBay was in an Oracle VirtualBox environment. They claim installation is "only 15 clicks, compared to 80 or more..." which is BS. Yeah, the full installer may take a few more clicks, but it's not that much more complicated. Piecing together the >30GB virtual environment is no picnic either. When it's all done, then you find out it won't run on older hardware with 32-bit CPU's, because the muppet installed Windows Home 64-bit as the OS inside the virtual container! Brilliant. Most newer PC's have 64-bit-capable CPU's, but keep this in mind if you have older hardware. Datacards were not enabled by default and the seller had no idea what I was talking about when I asked how to enable them. Maybe that has changed, maybe not. The VirtualBox environment is not user friendly, I was unable to change screen resolution in the virtual environment, so everything was "stretched" in the window. Supposedly this is fixable but I haven't figured out how.
Advantages: Supposedly works on Mac and Linux, since you are really running VirtualBox software, not the EPC/WIS directly. And there are no worries about the programs not "liking" your PC (granted, that is a rare occurrence with the full installer), assuming you can get the virtual environment working. All the other advantages from the standalone version applies (except the "speed" part).
Disadvantages: Doesn't work on older 32-bit hardware. And it is SLOW. Annoyingly slow. I couldn't use it daily. Irritating virtual environment problems like not being able to easily resize the screen/window without distorting the dispay. All the other disadvantages from the standalone version applies, other than the installation process.
Final comments: I got my full installation from eBay seller "amazing.events" located in the UK. It took them a while (over a week?) to ship it, but then it arrived in a few days. Tech support was better than expected, response via email was usually within a few hours. A keygen is included. Note that if you use torrent downloads, you may not be able to get the keygen. The MHA website wants you to pay for a membership to get the torrent stub file, then they won't even let you have the keygen, you need to post on their forum and ask for a key? Lame. Not to mention the hassle of trying to deal with torrent downloads over days or weeks. I got my VirtualBox install from eBay seller "nobodybeatsthewis". They were nice enough but had no clue what datacards were, let alone how to enable them. I contacted seller "anayalata" asking if they were selling a full installer or standalone. They replied if I meant VMware, I said yes, they never responded. I asked again a week later, no response at all. I would not buy from them. I later figured out that if a seller claims it runs on Mac/Linux, it's VMware of some sort. Buyer beware, etc.
Recommendations: If you only need occasional EPC access, and live in an "approved" country, the online/legal version is fine. If you are a hardcore user, and/or you need WIS access, get the full standalone install. I would not use the virtual environment packages unless you only have Mac or Linux, or if you are lucky enough to have one of the rare PC's that don't play nice with EWA.
Russian Online EPCs: Use only as a last resort. Their datacards are often incomplete and cannot be trusted. Links are here.