what does this mean, I leave my PC on all night so it can process all the projects, yet when it finishes them, it gives me this computation error. What does this mean?

It means the workunit didn't complete properly, Go and ask on whatever project the workunit was from,

Claggy

i get the same error on the climateprediction and on the milkyway, and sometimes on the SETI@home. Like I said I leave the pc running all night and day, so I don't know why it does this.

"Computation error" is a general statement that the BOINC back-end uses to show you quickly that something went wrong. In the stderr.txt that your BOINC sent to the projects there'll be a lot more information. This stderr.txt can be found in the TaskID of the task that had the computation error.

So far for the explanation. If you want more help, please exit & restart BOINC, then copy and post the start-up messages of your BOINC here in this thread. That way we can see what hostIDs your computer has at the various projects, and we can check for ourselves what your specific error is, and if it's a known one, offer help on it.

To exit BOINC, see this FAQ.
To restart BOINC, well, let's assume you have Windows, then you do Start->(All) Programs->BOINC->BOINC Manager.

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