Optiarc DVD RW unable to write disks after installing new Windows 7 on Dell Optiplex 755

I did try burning with Explorer, but I kept getting "Unable to format" error.

I even tried with another DVD RW drive. After Optiarc failed I bought a used TSST. Same result. I'm pretty sure that the seller wouldn't give me a faulty drive.

Since it is a year ago the burn function was working, it is possible that over the time interval it has lost the burn function although it can still read. Since you have clean Win 7 or 10 install, it is not a driver issue. You do not need third party software to burn dvd.  Try another blank dvd, right click on the DVD RW drive in Windows explorer, does it show “burn to this disc” option?  If yes try to burn something using Windows burn function and see if you still get an error.

Optical drives don't last forever.

A new Sata Drive with current nero is cheap.

https://www.newegg.com/bestduplicator-model-3y-qnce-ak4k-dvd-burner/p/1B1-0010-00086

https://www.amazon.com/Lite-AllWrite-IHAS124-04-KIT-Essentials-Software/dp/B00IIX2W7U/

I tried 11 HP disks in total, and one or two Maxell that I used last year (which I now see are DVD+R if it matters). I'm curious, have they become useless after receiving that error while burning?

I guess I'm going to be taking both burners back to the shop I got the TSST

In any case thanks for the quick replies.

Re: Unable to format

I have seen this error before in older Dell pc. first of all try another blank CD R or DVD R disc. Sometimes I got not just one but multiple duds in a factory lot of blank disks.  If you tried 5-6 discs they all give same error, chances are discs are not the culprit.
Then try install same burner in a different desktop pc and see it can burn disc normally. If yes that would prove something wrong with 755 OS, which would be strange if it is clean install.

Yes some blank disc become useless once Windows begin to attempt burning them even when no data is burnt.  Unfortunately they become toss aways.