The IBM/Windows version of PREPRO2023 comes with executable codes and data in compressed form - all of the files in the IBM package are in DOS format, ready to be used on my Windows/DOS system. 1) Copy IBMPC.tar.gz to your hard drive. First uncompress and untar - we recommend you use 7-zip, which is available FREE on the internet, or any similar uncompression code that you may have. After you have installed it should have a directory named IBMPC that contains 49 files and a directory named SOURCES; you can then delete IBMPC.tar.gz 2) To VERIFY proper installation, it is recommended that after install you execute VERIFY-IBMPC.BAT (Be sure to type the entire name, VERIFY-IBMPC.BAT, to avoid a conflict wth the DOS verify command). This is a batch file hat will run the codes in sequence. 3) The final two codes will display the calculated cross sections (EVALPLOT) and compare the results you calculated to a standard set (COMPLOT). Difference of about 1 % to 2% are acceptable; larger differences indicate installation problem. If plots are displayed before the batch file (VERIFY-IBMPC.BAT) finishes, the system has been verified and is ready to use. If you do not obtain plots there was an ERROR during installation; in this case see case 4) below. 4) If you have any problems notify the Nuclear Data Section, IAEA, Vienna, Austria. services@iaeand.iaea.or.at