Are you using TurboTax Online or the CD/Download version?
I am using the downloaded version. Each time I tried to update, I got a UPDATE FAILED.
If It's a Windows computer #1, make sure you've run and installed-rebooted after this week's Windows update. Sometimes a partially-installed Windows OS update will block proper operation of TTX.
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IF it's a Windows computer #2....downlaod and update using the "Manual" update.
It may take an unusually long time to process, so be patient...or go watch TV for 30 min.
.....and, you my need to try to run the internal update again, right after that manual update finishes.
Manually Update TurboTax for Windows Software (Basic, Deluxe, Premier, Home & Business) (intuit.com)
I tried the manual update and restarted my computer and am still running into the Failed Installation Message. Could the problem be that the return I need to amend has not been completely processed by IRS? It was accepted, but I have not received a refund yet.
TurboTax does not know if the return was processed by IRS. Check your internet speed. Try using a cord to connect instead of wireless.
Well the program doesn't know if the IRS has finished processing your return. Once Turbo Tax transmits your return and the IRS accepts it for processing then they are done with their part.
If you can't amend it might be because the program doesn't know it was accepted. For the Desktop program you have to check the filing status inside the program. Open your return and go up to menu item
File > Electronic Filing > Check Electronic Filing Status
Then save your return with the status. Go to File-Save.