The IBM/Windows version of PREPRO2019 comes with executable codes and data in compressed form. 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 PREPRO19 that contains 45 files; you can then delete IBMPC.tar.gz 2) To VERIFY proper installation, it is recommended that after install you execute VERIFY.BAT (Be sure to type the entire name, VERIFY.BAT, to avoid a conflict wth the DOS verify command). This is a batch file that 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.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