How PC makers exploited BIOS copyright strings to unlock trial software during the Windows 95 era

[Alfonso Maruccia]

What just happened? Jokingly referred to as "Plug and Pray" due to its notorious unreliability, the Plug and Play standard was nonetheless a pivotal advancement in simplifying hardware and peripheral configuration during the early Windows 9x era. Beyond easing setup for end users, the technology also played an unexpected role in exposing a cartel of PC manufacturers that had been exploiting a hardware feature to provide full versions of trial software packages to their customers.

Microsoft veteran Raymond Chen recently shared another behind-the-scenes story from the development days of Windows 9x, this time involving software copyright violations by dishonest PC manufacturers. According to Chen, some of these unnamed companies (disguised under fictitious brands in his post) managed to add extra software value to their hardware offerings while avoiding payments owed to legitimate software vendors.

The Windows 95 team stumbled upon this trick while working on Plug and Play technology. To ensure compatibility, they gathered a "very large" collection of PCs from various brands and models to identify systems sold before PnP was introduced. The goal was to retrofit PnP support onto legacy hardware, as initially no systems supported the standard.

To do this, Microsoft developers examined BIOS firmware, searching for copyright strings, firmware dates, and other identifiers. That's when they encountered a peculiar string embedded in one BIOS: Not Copyright Fabrikam Computer.

"Why would a BIOS deny that it was copyrighted? We weren't sure, but we had a theory," Chen said.

Back in the early 90s, branded PC systems were often sold with preinstalled software that was locked to a specific list of manufacturers. These "lite" versions of software would unlock premium features if they detected a particular string in the system BIOS; otherwise, users were limited to the basic, free-tier functionality.

For example, a string like "Copyright Fabrikam Computer" could trigger the full version of the software. However, competing manufacturers such as "Contoso" discovered this mechanism and attempted to exploit it. By adding a deceptive string like "Not Copyright Fabrikam Computer" to their own BIOS firmware, Contoso could trick the software into unlocking premium features without paying the required licensing fees.

The practice was likely illegal, as software piracy was already considered a serious offense even in the DOS era.

According to Chen, retrofitting a "modern" technology like Plug and Play onto older systems was an especially convoluted process. Developers had to carefully and intelligently probe the hardware without disrupting or confusing legacy, pre – Plug and Play equipment. The end result, as they say, is history.

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How PC makers exploited BIOS copyright strings to unlock trial software during the Windows 95 era

 

[unoficialoficial]

After the incident with the USB scanner and the BSOD during the presentation, they loaded a cart with 64 USB devices, all connected to 3 hubs. They then troubleshooted the OS USB connectivity behaviour by simultaneously connecting and disconnecting all of them at once through a single USB port.

 

[brucek]

Strange all around. Not sure it is or should be illegal to change your BIOS name to anything you want, and there plenty of examples of other kinds of system identifiers that are often fudged for compatibility reasons - take for example user agent strings in web browsers. If some software vendor wanted to build a licensing strategy around this that should be on them.

On the other hand not sure I see the benefit to the vendors either. This is only a marketing advantage if you can advertise to customers about it. And as soon as any of these vendors started adverttising their included free copies of X, Y, Z and that were not authorized by those companies, something would be done about it. So it's a nice surprise for the end user maybe but could only do so much to drive sales.

Fun story though, thanks for sharing it.

 

[candle86]

Strange all around. Not sure it is or should be illegal to change your BIOS name to anything you want, and there plenty of examples of other kinds of system identifiers that are often fudged for compatibility reasons - take for example user agent strings in web browsers. If some software vendor wanted to build a licensing strategy around this that should be on them.

On the other hand not sure I see the benefit to the vendors either. This is only a marketing advantage if you can advertise to customers about it. And as soon as any of these vendors started adverttising their included free copies of X, Y, Z and that were not authorized by those companies, something would be done about it. So it's a nice surprise for the end user maybe but could only do so much to drive sales.

Fun story though, thanks for sharing it.

So you think. The local mom and pop shops could do this pretty easily. I have bios editing software for really old bioses and an eprom programmer. It's not hard to add that string into the BIOS, old bios like current ones didn't always take up all of the sram. Ive got a biostat socket 3 board that really only needs 27k but to work on a 32k rom you have to just put in garbage at the back, in that garbage add these strings and suddenly a mom and pop shop can sell computers locally with the same software as a Compaq.


Something like this was done much later I even bought a computer without a valid windows XP sticker it had a coat but it wasn't a valid key because I tried to use it to reinstall. A little digging around and what I found out is they had flashed the BIOS with the slmgr string for HP, and then used an HP OEM disk to install Windows XP that they had stripped of all the HP stuff. Bought it from a little local computer store. I called him on it so he gave me the disc to reinstall it. Never got a valid COA.