When using Kaspersky Security Center as a WSUS server, the following folders will gradually increase in size: C:\ProgramData\KasperskyLab\adminkit\1093\.working\FTServer; C:\ProgramData\KasperskyLab\adminkit\1093\.working\wusfiles. You can empty not used Updates in the FTServer and wusfiles folders containing Microsoft updates in Kaspersky Security Center 11: https://support.kaspersky.com/15304