Cannot erase disc

[Navi]

I'm trying to burn a CD, but imgburn says that my discs ( TDK CD-R80) aren't empty while I'm sure they are empty.

I figured I should erase them with imgburn but then I get this meesage:

 

I 18:01:58 ImgBurn Version 2.5.6.0 started!

I 18:01:58 Microsoft Windows Vista Home Premium Edition (6.0, Build 6002 : Service Pack 2)

I 18:01:58 Total Physical Memory: 3.143.948 KB - Available: 1.465.912 KB

I 18:01:58 Initialising SPTI...

I 18:01:58 Searching for SCSI / ATAPI devices...

I 18:01:58 -> Drive 1 - Info: HL-DT-ST DVD+-RW GH50N B100 (D:) (ATA)

I 18:01:58 Found 1 DVD±RW/RAM!

I 18:03:43 Operation Started!

I 18:03:43 Device: [1:0:0] HL-DT-ST DVD+-RW GH50N B100 (D:) (ATA)

I 18:03:43 Media Type: CD-RW (Disc ID: 97m27s66f, Ricoh Co.)

I 18:03:43 Media Supported Write Speeds: 4x; 8x; 16x; 24x; 32x; 40x

I 18:03:43 Quick Erase: No

I 18:03:43 Erasing Disc...

E 18:03:55 Failed to Erase Disc! - Reason: Cannot Write Medium - Incompatible Format

E 18:03:55 Operation Failed! - Duration: 00:00:11

 

Please.....Help

[LIGHTNING UK!]

You can't erase a disc if it isn't a rewritable one in the first place.

 

Put a new disc in the drive, switch to 'Write' mode and then copy + paste everything from the disc info box on the right please.