Updated 2012-06-28 11:55:18 by RLE

fr Workaround on W2k/XP systems crashing after some days. Script placed in Autostart provides a daily automatic restart at given time. Requires ffidl and AutoIt. Needs Autologon configured in registry.
 proc stop_jobs {} {
   # final actions before shutdown
 proc shut_message {delayseconds} {
   toplevel .shut -background red
   bind .shut <Any-Key> {exit}
   label .shut.l -background yellow -font {Verdana 30} \
     -text "System restarts in $delayseconds seconds!\nPress any key to cancel"
   pack .shut.l -padx 30 -pady 30
   focus -force .shut
   after [expr $delayseconds*1000] {set ::waited 1}
 if {[regexp -nocase windows $::env(OS)]} {
   package require Tk
   load ffidl05.dll
   set DLL AutoItDLL.dll
   ffidl::callout AUTOIT_Shutdown {int} int [ffidl::symbol $DLL AUTOIT_Shutdown]
   set now [clock seconds]
   set shutdown_time 17:19:00
   . configure -bg green
   wm overrideredirect . 1
   label .l -text "The system will restart at $shutdown_time !" -font {Courier 16}
   pack .l -padx 20 -pady 20
   after 2000 {set ::infovar 1}
   vwait ::infovar
   wm withdraw .
   set fin [clock scan $shutdown_time]
   if {$fin<$now} {
     incr fin [expr 3600*24]
   set delay [expr $fin - $now]
   set delay [expr $delay * 1000]
   after $delay {
     shut_message 60
     vwait ::waited
     AUTOIT_Shutdown 3
   vwait forever

MHo: Much more simple is this: at hh:mm /every: datespec[,...] "shutdown -r". Both tools are in my Windows/System32-Folder on my home system (Windows/XP). They should be installed on almost every modern Win-System. But nevertheless, your solution is very interesting... (Sometimes windows is not as dump as it seems....)