I just burned a DVD with Infra Recorder, so I can confirm that the solution I posted above works to get the DVD drive working again.
So you may need to repair your registry if you don’t have any other options in order to replace your NTI CD/DVD maker application. Just restoring UBHelper.sys from the Avast vault won’t fix this. Thanks for the info erix2. SEE both of erix2’s posts above to follow his advice. Looks like reinstalling the drivers and application software won’t fix the CD or DVD drive unless the software will repair the registry…
This problem sure is getting messy. If you don’t have an older restore point than this issue, there doesn’t seem to be a simple repair unless your are comfortable with editing your registry.
I have submitted a ticket on this issue and I hope others have also. https://support.avast.com/
@busp1: To clarify, the operation on the registry is not a repair but a removal of a residual driver of the NTI application.
I think reinstalling the NTI application should also restore drive functionality, but unfortunately on my old Acer (Aspire 630T) this does not appear to be possible. Probably because that old software is not compatible anymore with XP SP3.
It has been 2 days now that a scan has not returned a warning on UBHelper.sys. My guess is that Avast techs have fixed the problem. Still no reply to my ticket on this problem so no confirmation it was a false positive. I will post back if I ever get a reply form the ticket.
Till next time.
I can confirm that I don’t have new warning popup for rootkit UBHelper.sys on Avast 
and the problem is successfully solved for my desktop ;D
For all owners of computers Acer, the appropriate solution is :
[ol]- Open the Device Manager and UNINSTALL your DVD/CD rom drive who is actually unrecognized.
- UNINSTALL ALL NTI software.
- MADE a reboot and your CD-DVD drive is automatically reinstalled by Windows Plug and Play technology.[/ol]
Good Luck !
(and if it doesn’t work, go here: http://answers.microsoft.com/en-us/windows/forum/windows_7-hardware/dvdcd-driver-ubhelpersys-blocked/31be8e17-6a3b-44fc-90e5-0f7668762b23 you can solve the problem by using Microsoft fix-it software)
Thank you for contacting AVAST Software.
The file “UBHelper.sys” you sent seems to be undetected by Avast with the latest virus definition.
In case if Avast is still detecting the file and moving it to the Virus Chest, you can restore the file from Virus Chest(Quarantine) and create an exclusion this way:
Open Avast > Scan > (Scan for viruses in Avast 2015) > Quarantine (Virus Chest) > select the file you want to restore, right-click on it and click on “Restore and add to exclusions”.
If you need further assistance, please don’t hesitate to contact me again.
Best regards,
Rojan Piya
Technical support | AVAST Software s.r.o.