We have an intermittent problem with our terminal servers, where one of the svchost processes crashes, and then nobody is able to log in including the administrator account. Any users already logged in can still keep working (although some programs will refuse to run) and so far we've only fixed it by restarting the server when it happens.
Application Error, ID - 1000
Faulting application name: svchost.exe_TermService, version: 6.1.7600.16385, time stamp: 0x4a5bc3c1
Faulting module name: unknown, version: 0.0.0.0, time stamp: 0x00000000
Exception code: 0xc0000005
Fault offset: 0x0000000000000000
Faulting process id: 0x104c
Faulting application start time: 0x01cbe1e12a2c8bdf
Faulting application path: C:\Windows\System32\svchost.exe
Faulting module path: unknown
Report Id: 730e4767-4f55-11e0-aa51-00059a3c7800
Both servers are running Server 2008 R2 Standard, 64-bit, and Citrix XenApp 6, with the latest updates.