Some recent versions of NTP
These versions will run on 32-bit and 64-bit Windows, and are working for me. They were compiled with Visual Studio 2015 Community Edition with the "Run on XP" and 32-bit options set to allow running on Windows XP SP3 and later, but they will not run on Windows 2000 - Windows XP SP3 or later is required. By default, VS2015 produces executables requiring Windows Vista or later, and Pentium SSE2 instructions, but these settings can be overridden and have been overridden in the versions offered below so that Windows XP SP3 is still supported. There is more information in this bug report.
Other updates your PC might need
You may need the Visual C++ Redistributable Packages for Visual Studio 2015 from Microsoft, which you can download here if they are absent from your PC.
Your system may need an update of SSL. You can try either:
You can see what NTP versions are in current use on my systems here.
They are from the release branch of the NTP source. The most recent is listed last in the list below. Right-click, Save... to download. You take responsibility for using them, although I do try to test them for basic functionality here before release on Win-XP/32, Win-10/32 and Win-10/64 including some stratum-1 PCs. They should work on all versions of Windows from XP-SP3 and later. I assume that you know what you are doing if you use these versions - here is a very brief installation note. Caveat emptor!
The following versions will normally be the VS2015 tree compiled with Microsoft Visual Studio 2015 Community Edition, using the "Run on XP" project settings.
Loopback PPS provider
You can find some GPS/PPS devices suitable for use with NTP here, and I've also used these with FreeBSD and Linux. There is a quick-start guide for the Raspberry Pi including PPS and configuration notes for NTP. My main Windows setup notes are here.
Jottings from the archive
Between NTP 4.2.7p349 and NTP 4.2.7p356, with VS2010, a small edit was required to two of the files which were incorrectly automatically generated. The fixes are described here.
Dave Hart has many more versions available in both release and debug versions, and
with symbols files - these may be downloaded here.
There are some notes on the updating process here.
My thanks for Dave Hart
for his help in getting the Windows compilation to work, and in providing the
appropriate version of the OpenSSL library. If you want to do the
compilation yourself, I have provided some notes here.
See what version my own PCs are running
PC Bacchus is a Windows 2000 PC, so it relies on versions which others have
compiled. PC Pixie is an Intel Linux system, and the Raspberry Pi cards are
ARM Linux systems,
so they may have a separate compile cycle. Unless it's a significant update,
I might only test on one Raspberry Pi system. They are all running the same OS
(Raspbian), but some run Wheezy and some Jessie or later. I find that the
Wheezy-compiled version runs on Jessie, but the Jessie-compiled version uses a
library which isn't available on Wheezy, so for now I compile on Wheezy and run
on both Wheezy and Jessie.