BOINC versions tried: 6.10.58, 6.2.19, both under XP-32 SP3

If you are reinstalling BOINC and there is no longer a device with the same Windows drive letter as the one that held the BOINC data for the previous installation, the installer will fail with the popup message: "Error 1327.Invalid Drive: X:\", where X is the letter of the drive that previously held the data.
Instead of failing, the installers should take the user to a screen from which a valid new data location can be specified. Bug #1.

The failure persists through uninstalling the previous BOINC installation using Control Panel >> Add or Remove Programs. The uninstaller should remove all traces of a BOINC installation. Bug #2 - already reportd to BOINC developers, see links below.

Workarounds:
- Temporarily reinstate a drive that has the same letter as the one that previously held the BOINC data. The drive can be a USB flash RAM stick.
(Drive letters can be changed if necessary using Control Panel >> Administrative Tools >> Computer Management >> Storage >> Disk Management, and right-clicking on the drive or partition that you want to change.)
- Try the BOINC Uninstall Clean Up Utility V1.0 linked in the WCG FAQs Index: Uninstalling BOINC & Post-Cleanup . [I should have looked in the FAQs first! ]
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OK, so I got as far as successfully reinstalling BOINC with a different data drive:
- suspended BOINC activity in BOINC Manager
- Stopped BOINC using Admin Tools >> Services.
- copied the BOINC data directory from drive F: onto a USB stick
- unplugged the drive that was F: and plugged in another drive that Windows mounted as D:
- copied the data from the USB stick to D:
- After installer failures, plugged the USB stick in again, and found it was mounted as F:, so I didn't have to change its letter to reinstall BOINC.
- reinstalled BOINC with data on D: instead of F:.
- Started the BOINC service and BOINC Manager.
More problems!
BOINC Manager couldn't find a client.
boinc.exe had disappeared from (Task Manager >> Processes), but (Admin Tools >> Services) thought the service was still running and that it just wouldn't respond to commands after a reasonable period.
I uninstalled BOINC from Ctrl Panel. Got a "Fatal error" on first try, but succeeded on the second. Reinstalled BOINC. This time, BOINC Manager briefly saw all of the suspended tasks from the previous installation, but they disappeared, and boinc.exe had quit. After another uninstall-reinstall cycle or two, the suspended tasks stayed in BOINC Manager, but the previously-running tasks remained Waiting to run when I set Run Always. After yet more uninstall-reinstall cycles, the tasks started running and everything has been running smoothly since. Bug #3 must be in there somewhere.
I was pleased that the re-runs of the BOINC installer left untouched the BOINC data that I had copied onto the new drive, so I did not have to restore it a second time.
Changing the drive was not a user-friendly process!
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[ot] Why did I change the BOINC data drive? With the previous drive, the system was pausing with the HDD activity LED fully on for long enough to cause WUs to time out, exit with the messages:
"No heartbeat from core client for 30 sec - exiting" in the CEP2 WUs Results Status logs, and in the BOINC Messages tab:
"Task ttttt exited with zero status but no 'finished' file
"If this happens repeatedly you may need to reset the project.",
and then be restarted from their last checkpoints or their beginnings.
See my posts in the CEP2 Forum at work units not finishing and Will CEP2 units eventually NOT Bogart the host when they start up? , plus My thread @ XS > WCG - WCG tasks die &quot...;finished' file" .
The change of BOINC data drive is looking good so far ... no exits & restarts in 24 hours. [/ot]