The 158-page bundle of internal Microsoft e-mails (PDF) that Judge Martha Pechman ordered unsealed as part of the ongoing "Vista Capable" lawsuit contains a great deal of interesting information. We've previously covered how the e-mails within the evidentiary document describe the changes Microsoft made to the definition of Vista Capable in order to improve Intel's quarterly earnings, but that's not the only gem within the document. According to Microsoft's own included documentation, the widespread reports of NVIDIA Vista driver issues were by no means exaggerated during Vista's first months.

NVIDIA had significant problems when it came time to transition its shiny, new G80 architecture from Windows XP to Windows Vista. The company's first G80-compatible Vista driver ended up being delayed from December to the end of January, and even then was available only as a beta download. In this case, full compatibility and stability did not come quickly, and the Internet is scattered with reports detailing graphics driver issues when using G80 processors for the entirely of 2007. There was always a question, however, of whether or not the problems were really that bad, or if reporting bias was painting a more negative picture of the current situation than what was actually occurring.

Microsoft's data strongly indicates that the problems were real. Damon Poeter at CRN dug through the documentation to find that on page 47 of the PDF, NVIDIA drivers were identified as the cause of over 479,000 crashes, or just under 29 percent of all the crashes Microsoft logged. Microsoft's own drivers follow, at 17.9 percent, and the "Unknown" category takes third place at 17 percent. ATI is in fourth place (9.3 percent) and Intel in fifth place (8.83 percent).

The data points in the table cover an unspecified period in 2007, and Microsoft makes no attempt to break the aggregate data down into which device drivers, specifically, returned the highest number of crashes. If the number of failures were split by month and then graphed, we'd presumably see the number of NVIDIA driver failures per month decreasing as the company slowly brought its driver issues under control.

The data clearly indicates that NVIDIA had a driver problem, but it's impossible to quantify the scope of that problem given the numbers above. NVIDIA holds a greater percentage of the market than ATI, which means that there will inevitably be a higher percentage of NVIDIA driver crashes than ATI driver crashes; however, the degree to which such market share considerations have affected the results above is hard to determine in the absence of more data. There's also the matter of data collection; Microsoft's charts do not clarify if multiple crashes from a single system each counted as separate events. In theory, NVIDIA's proportion of total driver crashes could be inflated by a relatively small handful of systems with severe driver issues.

Driver problems are nothing new, particularly during the launch of a new OS, but the high incidence of NVIDIA driver crashes may have fueled public perception of Vista as an unstable and buggy OS. Microsoft has always billed DirectX 10 as a next-generation enthusiast feature, but in early 2007 the only DX10-capable parts were limping under the combined burden of buggy drivers and the increased computational demands of DX10 games. NVIDIA's early-to-midyear Vista issues may not have counted for much, given that few consumers actually purchase enthusiast-level graphics cards, but the company's problems were an additional drag on the perception of Vista at a time when Redmond could least afford it.