This was copied directly from Gail's site under FAQ's :
Q 414: How can I get the programs to run in 64-bit XP, Vista, or 7?
A: Our current software will only run on 32-bit versions of Windows (with the exception of the new FFWG and FWGP programs). There is no compatibility with WinXP-64, Vista-64, or Windows 7-64, with the exception of Windows 7 Pro running in 32-bit XP mode. Microsoft omitted including the DOS emulation software, vdm32.dll that has been part of all other version of Windows since Win95. Therefore according to Microsoft, there is NO way to run any 16-bit software on 64-bit versions of Windows. Because of this, we can't release just a simple patch. Each program has to be completely rewritten.
However, there are still options for running our software. The immediate options are:
Upgrade to Windows 7 Pro
If you have Windows XP, Vista, or Home Premium, you can buy an upgrade to Windows 7 Professional. This is the best option. You can upgrade Windows 7 Home Premium to Windows 7 Professional for $89 directly from Microsoft and Windows Vista can be upgraded to Windows 7 Professional for around $200 or less from any retail source. Machines with Windows XP usually do not have the right hardware to be able to upgrade to Windows 7 Pro. Get more information about upgrading, installing XP mode, or determining your version of Windows.
Dual Booting
Install a 32-bit version of Windows as a dual boot (that means when you restart your computer, you select to run 32 bit Windows or 64 bit Windows. This is probably the least expensive option because you can install an oem version of windows that costs about half what a full version costs. You can install any 32 bit version of Windows as the dual boot. See Microsoft support on dual-booting.
Downgrade Your Operating System
You can have the people who sold you the computer replace your 64 bit operating system with a 32 bit version of the same. At this time, you will see absolutely no difference, since no one is producing programs yet that only run on 64 bit windows. The majority of computers out there are still 32-bit and all programs run on those.
Virtual Machine
Install Microsoft's free virtual machine software (or any of several other free virtual machines) and then install a full version of 32-bit Windows inside that virtual machine. Microsoft Virtual Machine 2007 which is a free download from Microsoft and which we are told is actually on the 64-bit Windows dvd's, can be relatively easily installed. Advantages of this are that you can bring up the virtual machine with just a mouse click and switch back to you main operating system just as quickly (like having two machines in one). However the full version of windows that is required is expensive (xp-pro can cost around $320). If you can find a copy of an older version of Windows like Win 2000 or Win 98 or Win ME (perhaps from an old machine that has died), they do not require activation and can therefore be installed in a VM without a problem, though they are more complicated to install in a vm. Before trying this, we recommend searching in your preffered search engine for "how to install Win98 in VPC 2007" to find a set of step-by-step instructions. These steps were are not necessarily obvious, so finding instructions could save you a lot of time.
Buy a used 32-bit Operating System Computer
There are many low cost computers available that use XP or 32-bit Vista. 64-bit Vista has only been generally sold on new machines. You can find these computers for sale in shoppers, Craigslist, and other sources for as little as $50. Many younger users are always trading up to the fastest latest computers to play the top video games and their old machines are still perfectly good machines.
DOSBox
You can physically run the programs very well with the free DOSBox DOS emulator program available from Sourceforge. Unfortunately, DOSBox has a problem the other way -- it will not run any 32-bit or other Windows programs, and our DOS programs need that in order to print on USB printers. DOSBox does not provide any way to print.
Instructions for DOSBox:
1) Install DOSBox from SourceForge
2) Then click "DOSBox 0.74"
3) At DOS prompt, type "mount c c:\GH\"
4)Type c: (To switch to the new mounted position)
5) Then type "gail.exe" and DOS Advantage Plus will pop up