As some of you who use spinrite very frequently may have noticed, spinrite will usually crash when scanning larger drives (in my experiences it's been on drives over 640GB). Once spinrite gets to a certain point in the scan, it will throw up a red screen with a “Division Overflow Error'. This usually occurred over 50% into the scan depending on the size of the drive.

After researching the error online, it appears that it’s not a problem with spinrite but an issue with the FreeDOS (MS-DOS) clone that Steve Gibson bundles with spinrite.

This is an article on how to fix this.