Check Event Viewer for Error 2138 – Drives running out of space.
Sharepoint will report health errors if the C:\ has less space than 2x installed RAM.
SharePoint Central Admin > Monitoring > Health Analyzer > Review rule definitions > under Availability > ‘Drives are running out of free space’
Patching SharePoint Foundation 2010 is a two-step process. The updated binaries are first installed and then psconfig must be run to update the SharePoint databases.
In order to update the SharePoint databases, you must manually run the PSconfig utility. To run the utility:
1. Open an Administrative command prompt.
2. Change directory to C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\14\BIN
3. Run PSConfig.exe -cmd upgrade -inplace b2b -force -cmd applicationcontent -install -cmd installfeatures
Source – Microsoft KB2580174