[Vayrus]

Попробуйте данный код:

Код:

function GetWindowsInstallDateTime: TDateTime; 
const 
RegKeyNT = 'SOFTWARE\Microsoft\Windows NT\CurrentVersion'; 
RegValNT = 'InstallDate'; 
RegKey95 = 'SOFTWARE\Microsoft\Windows\CurrentVersion'; 
RegVal95 = 'FirstInstallDateTime'; 
function RegReadDWORD(const Key, Name: string): DWORD; 
begin 
Result := 0; 
with TRegistry.Create do 
try 
RootKey := HKEY_LOCAL_MACHINE; 
if KeyExists(Key) and OpenKeyReadOnly(Key) and ValueExists(Name) and 
(GetDataType(Name) in [rdInteger, rdBinary, rdUnknown]) and 
(GetDataSize(Name) = SizeOf(Result)) then 
if GetDataType(Name) = rdInteger then 
Result := DWORD(ReadInteger(Name)) 
else 
ReadBinaryData(Name, Result, SizeOf(Result)); 
finally 
Free; 
end; 
end; 
var 
Value: DWORD; 
begin 
Value := RegReadDWORD(RegKeyNT, RegValNT); 
if Value <> 0 then 
Result := EncodeDate(1970, 1, 1) + (Value / SecsPerDay) 
else 
begin 
Value := RegReadDWORD(RegKey95, RegVal95); 
if Value <> 0 then 
Result := FileDateToDateTime(Value) 
else 
Result := 0.0; 
end; 
end;