It is a bad idea to install one version of CVI into the same directory as another version. This effectively merges the two installations, even though your system considers them separate, distinct installations. You should instead first uninstall CVI 8.0.1 or install CVI 8.1 to a new directory. As a general rule, you should rerun any driver or toolkit installers whenever you install a new version of CVI to be sure everything works properly. However, if you are installing CVI to the same directory as the old version, I believe you can get by without reinstalling your drivers/toolkits. The driver/toolkit files should be left behind when CVI 8.0.1 uninstalls, and you should be able to install CVI 8.1 into the directory that gets left behind.
As a side note, just in case you are using the CVI RT module, you do not want to uninstall CVI 8.0.1 quite yet. The CVI RT 8.0 module is only compatible with the CVI 8.0.x environment. As the CVI RT 8.1 module has not yet been released, you must continue to use CVI 8.0.1 if you want to target RT systems.
Let me know if you run into any issues.
Mert A.
National Instruments
