This was used for Newton to Ringo no Ki, but should work (with some modifications) for most cs2 vns.

If using a steam version

Download steamless on a newer computer and patch cs2.bin in the game folder

For all users

rename cs2.bin to cs2.exe

download and extract this

copy cs2.exe to the folder where you extracted the downloaded file

create a file in this folder and call it cs2patch.cmd. In this file, paste:

rundll32.exe zernel32.dll,PatchFile cs2.exe

double-click the file and run it

once you see a dialog saying game patched, copy all the contents of the folder back to the game folder

copy the game folder to the xp computer

to run the game, double-click cs2.exe

Credits

UncleVasya / Oleg Ovcharenko for the patcher

thrawn of xin.at for the nekopara vol 3 tutorial this is based on