Sorry for my late response. @kiki burgh I've checked my installer with /S switch and it seems to work just fine, there will only be a little DOS screen that will still shows up and close automatically. If you are using this with WPI then make sure you have the right quotation. This is from my WPI config file: prog[pn]=['Windows Vista Sidebar Installer 1.1 *']; ordr[pn]=[22]; desc[pn]=['Windows Vista Sidebar for Windows XP']; uid[pn]=['WVS']; dflt[pn]=['yes']; cat[pn]=['Microsoft Softwares']; forc[pn]=['no']; cmd1[pn]=['"%wpipath%\\Install\\WindowsXPSidebarInstaller-1.1.exe" /S']; pn++; Also, if you still see the black clock, please re-run the installer again and see if it is still got the same error or not? I need to know where did it wnet wrong. Thank you @modarm Do you still see this error every time you reboot? And Do you have Windows XP64-bit installed on the same partition?