You bet there's a way. The simplest solution is:
1. Set the FlatStyle property of all your controls to System.
2. Put this into a file called <application name>.exe.manifest
(Where <application name> is your app's file name.)
3. Put the file into the same directory as your .exe file.
Code:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
<assemblyIdentity
version="1.0.0.0"
processorArchitecture="x86"
name="Application"
type="win32" />
<description>
An application that usesthe themed ctls.
</description>
<dependency>
<dependentAssembly>
<assemblyIdentity
type="win32"
name="Microsoft.Windows.Common-Controls"
version="6.0.0.0"
publicKeyToken="6595b64144ccf1df"
language="*"
processorArchitecture="x86" />
</dependentAssembly>
</dependency>
</assembly>
There is a way to merge this file into your .exe so you don't have two different files but you asked for a simple way. Merging is a bit tricky and you need to use a different manifest file I think. To find out how, just do a simple search on yahoo or google.
BTW, this method I described also works for VB6 .exe's.