When I try to install the latest version it looks for a non-existent drive and won't proceed. How do I change this? Any suggestions?

What do you mean exactly? Are you saying you can't change the path to the installation directory as you would usually do?

Is it an error message that you get? Something like The feature you are trying to use is on a network resource that is unavailable. ??

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it says: Error 1327.Invalid Drive: F:\

When I click on OK, the installation aborts.

Did you before install BOINC from a removable drive, such as a network drive or a USB stick, or did your drive letter change between installs?

You could try to follow the steps at this Installshield FAQ. But I think it's best if you downloaded the Windows Installer Clean Up utility anyway (link to it is in the FAQ in my previous post) and use it to delete the BOINC.msi file that may be in your way. Don't delete other .msi files!!

If that doesn't fix it, edit the registry.
Start->Run, type regedit and click OK
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Space Sciences Laboratory, U.C. Berkeley
Delete this whole key.
Exit regedit.
Reboot the computer (or log off/log back on).

Try to install BOINC now.

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