Two things not to turn off
1. Tablet pc functions. Disabling this turns off Snipping tool. An extremely helpful tool on Vista.
2. Error reporting.
Anyone who claims that your report just ends up in a big ol’ pile of reports on the same problem and it doesn’t do any good hasn’t clicked on the Problems resolution tab in Vista in a while. It does help to not only alert Microsoft of trending issues (because Lord knows we don’t call Microsoft and alert them) but it also does it more effliciently and effectively than anything we can do verbally. Every piece of software I see built today has this reporting feature.
It also points out that the author hasn’t done their research in understanding how this information is used. Mark Russinovich in the Windows Internals book talks about how great this feedback information is.