There's a sticky for this, I'm sure. But all you have to do is set the compatability for the EXE file to Windows 95 (not sure but I think 98 might work too).
Here's what you do:
Open up my Computer and navigate your way to the directory containing the Secret Ops Executeable File (EXE)
Right click on the file and select "Properties". At the top there should be a tab for "Compatability". Select that tab and from the drop down list select the right option (Windows 95) and then hit apply, and okay.
That's all it takes - just make sure you run that EXE when you want to start the game.
For Standoff I think the instructions are exactly the same (You may also need HCL's high-res pack for Secret Ops, you'd have to ask them about it - in addition it may not need to be run in win95 compatability mode, I don't know for sure).