This applies to both FreeSpace 1 and 2 which have the following bugs (tested on Windows XP):

- Afterburner does not work
- Briefing stalls in the first screen and does not advance

This is due to a too fast CPU - the GOG minimum requirements are bogus: FreeSpace was desigend for a target CPU frequency of 133 to 166 MHz. The game uses QueryPerformanceCounter() for timing and does not get it right on today's GHz CPUs.

Of course, such a bug should properly be fixed in the game itself before rereleasing it marked as "compatible with Windows XP" and "1.4 GHz CPU recommended" . ;-)

There is a bogus solution out there to enable Windows 95/98 compatibility mode. But introduces a new bug:

- Input lag with hardware rendering

I developed a solution using Microsoft Application Compatibility Toolkit 5.6: http://www.microsoft.com/downloads/details.aspx?familyid=24DA89E9-B581-47B0-B45E-492DD6DA2971

1. Download "Application Compatibility Toolkit.msi" using the link above.
2. Download http://www.oldgasworks.org.uk/FreeSpace.sdb for FreeSpace 1 (Mirror: https://mega.co.nz/#!c4xRBaIb!AdaXeW5OmYJ0MRlZqnulOAdMGt4ovWYmWJJLt-rnwLA )
3. Download http://www.oldgasworks.org.uk/FreeSpace2.sdb for FreeSpace 2 (Mirror: https://mega.co.nz/#!E0IAEY6S!TJRTjRqdtwzxq1ObO-4vwQoSvN1NVnDjzpoaK17kSow )
4. Install "Application Compatibility Toolkit.msi"
5. Run "Compatibility Administrator" from the "Microsoft Application Compatibility Toolkit 5.5" program group
6. Select "Open" and open FreeSpace.sdb
7. Right-click "FreeSpace [...FreeSpace.sdb]" under "Custom Databases" and select "Install"
7. Select "Open" and open FreeSpace2.sdb
8. Right-click "FreeSpace2 [...FreeSpace2.sdb] under "Custom Databases" and select "Install"
9. Close "Compatibility Administrator"
10. If you previously had enabled Windows 95/98 compatibility mode on your FreeSpace or FreeSpace 2 shortcuts respective FS.exe or FS2.exe, go to its properties and disable any compatibility options.
11. If you previously disabled hardware rendering, run FreeSpace.exe or FreeSpace2.exe, select Setup and re-enable it.
11. Done

Now afterburner and briefing screens should work and no input lag should occur.

Have fun!

Edit: Mirrors for sdb files added, thank you, simonhales

Thanks for the mirrors simonhales.
What graphics hardware and driver version did you use? AMD/ATI or nVidia? FS2 runs fine on my nVidia 9600 GT with 512 MB on XP x64.
I already know of FSOpen and hard-light.net (the campaign walkthroughs there are very helpful). A killer feature of FSOpen is its support for TrackIR ( http://www.naturalpoint.com/trackir ). It takes some time to setup. It would be nice to get a ready to run FSOpen package from GOG like their bundled DOSBox versions. But I will complete the FS1 campaign first, before I get into this.

It's not working. I cannot dowload the freespace sdb file as anything but a text file, and then the Microsoft Program will not recognize it.

Seriously, just get FS2_Open. It's just that much better, and easier to work with than this somewhat ugly hack.

Thanks for this, it worked great for me and fixed the afterburner.

EDIT: Thanks JTSN! Also, if anybody is having problems downloading the .sdb file as anything other than a text file, you'll need to right-click the link and select "save as", change the file category to "all files" and add .sdb at the end, otherwise Internet Explorer (at least on XP) will try to handle it as a text file.

The links need to be updated, the primary and mirrors do not work anymore

Dead links removed, all mirrors updated, Downloads should work again.

Again, dead mirrors removed. Mirror links updated.

well your mileage may vary - I don't know if everyone who plays the vanilla version of Freespace encounters this problem on all OSes, but if you do, you can try the fix in this thread - or use the Freespace Open Engine which makes everything modern, compatible, and very nice to look at.

*bump* because most users overlook this solution - all links are still working.

mirrors updated