diff --git a/src/windows-emulator/context_frame.cpp b/src/windows-emulator/context_frame.cpp
index 01bd06d0..e7adf26b 100644
--- a/src/windows-emulator/context_frame.cpp
+++ b/src/windows-emulator/context_frame.cpp
@@ -5,7 +5,7 @@ namespace context_frame
 {
     void restore(x64_emulator& emu, const CONTEXT64& context)
     {
-        if (context.ContextFlags & CONTEXT_DEBUG_REGISTERS_64)
+        if ((context.ContextFlags & CONTEXT_DEBUG_REGISTERS_64) == CONTEXT_DEBUG_REGISTERS_64)
         {
             emu.reg(x64_register::dr0, context.Dr0);
             emu.reg(x64_register::dr1, context.Dr1);
@@ -15,7 +15,7 @@ namespace context_frame
             emu.reg(x64_register::dr7, context.Dr7);
         }
 
-        if (context.ContextFlags & CONTEXT_CONTROL_64)
+        if ((context.ContextFlags & CONTEXT_CONTROL_64) == CONTEXT_CONTROL_64)
         {
             emu.reg<uint16_t>(x64_register::ss, context.SegSs);
             emu.reg<uint16_t>(x64_register::cs, context.SegCs);
@@ -26,7 +26,7 @@ namespace context_frame
             emu.reg<uint32_t>(x64_register::eflags, context.EFlags);
         }
 
-        if (context.ContextFlags & CONTEXT_INTEGER_64)
+        if ((context.ContextFlags & CONTEXT_INTEGER_64) == CONTEXT_INTEGER_64)
         {
             emu.reg(x64_register::rax, context.Rax);
             emu.reg(x64_register::rbx, context.Rbx);
@@ -45,7 +45,7 @@ namespace context_frame
             emu.reg(x64_register::r15, context.R15);
         }
 
-        /*if (context.ContextFlags & CONTEXT_SEGMENTS)
+        /*if ((context.ContextFlags & CONTEXT_SEGMENTS) == CONTEXT_SEGMENTS)
         {
             emu.reg<uint16_t>(x64_register::ds, context.SegDs);
             emu.reg<uint16_t>(x64_register::es, context.SegEs);
@@ -53,7 +53,7 @@ namespace context_frame
             emu.reg<uint16_t>(x64_register::gs, context.SegGs);
         }*/
 
-        if (context.ContextFlags & CONTEXT_FLOATING_POINT_64)
+        if ((context.ContextFlags & CONTEXT_FLOATING_POINT_64) == CONTEXT_FLOATING_POINT_64)
         {
             emu.reg<uint16_t>(x64_register::fpcw, context.FltSave.ControlWord);
             emu.reg<uint16_t>(x64_register::fpsw, context.FltSave.StatusWord);
@@ -66,7 +66,7 @@ namespace context_frame
             }
         }
 
-        if (context.ContextFlags & CONTEXT_XSTATE_64)
+        if ((context.ContextFlags & CONTEXT_XSTATE_64) == CONTEXT_XSTATE_64)
         {
             emu.reg<uint32_t>(x64_register::mxcsr, context.MxCsr);
 
@@ -80,7 +80,7 @@ namespace context_frame
 
     void save(x64_emulator& emu, CONTEXT64& context)
     {
-        if (context.ContextFlags & CONTEXT_DEBUG_REGISTERS_64)
+        if ((context.ContextFlags & CONTEXT_DEBUG_REGISTERS_64) == CONTEXT_DEBUG_REGISTERS_64)
         {
             context.Dr0 = emu.reg(x64_register::dr0);
             context.Dr1 = emu.reg(x64_register::dr1);
@@ -90,7 +90,7 @@ namespace context_frame
             context.Dr7 = emu.reg(x64_register::dr7);
         }
 
-        if (context.ContextFlags & CONTEXT_CONTROL_64)
+        if ((context.ContextFlags & CONTEXT_CONTROL_64) == CONTEXT_CONTROL_64)
         {
             context.SegSs = emu.reg<uint16_t>(x64_register::ss);
             context.SegCs = emu.reg<uint16_t>(x64_register::cs);
@@ -99,7 +99,7 @@ namespace context_frame
             context.EFlags = emu.reg<uint32_t>(x64_register::eflags);
         }
 
-        if (context.ContextFlags & CONTEXT_INTEGER_64)
+        if ((context.ContextFlags & CONTEXT_INTEGER_64) == CONTEXT_INTEGER_64)
         {
             context.Rax = emu.reg(x64_register::rax);
             context.Rbx = emu.reg(x64_register::rbx);
@@ -118,7 +118,7 @@ namespace context_frame
             context.R15 = emu.reg(x64_register::r15);
         }
 
-        if (context.ContextFlags & CONTEXT_SEGMENTS_64)
+        if ((context.ContextFlags & CONTEXT_SEGMENTS_64) == CONTEXT_SEGMENTS_64)
         {
             context.SegDs = emu.reg<uint16_t>(x64_register::ds);
             context.SegEs = emu.reg<uint16_t>(x64_register::es);
@@ -126,7 +126,7 @@ namespace context_frame
             context.SegGs = emu.reg<uint16_t>(x64_register::gs);
         }
 
-        if (context.ContextFlags & CONTEXT_FLOATING_POINT_64)
+        if ((context.ContextFlags & CONTEXT_FLOATING_POINT_64) == CONTEXT_FLOATING_POINT_64)
         {
             context.FltSave.ControlWord = emu.reg<uint16_t>(x64_register::fpcw);
             context.FltSave.StatusWord = emu.reg<uint16_t>(x64_register::fpsw);
@@ -138,7 +138,7 @@ namespace context_frame
             }
         }
 
-        if (context.ContextFlags & CONTEXT_XSTATE_64)
+        if ((context.ContextFlags & CONTEXT_XSTATE_64) == CONTEXT_INTEGER_64)
         {
             context.MxCsr = emu.reg<uint32_t>(x64_register::mxcsr);
             for (int i = 0; i < 16; i++)
diff --git a/src/windows-emulator/syscalls.cpp b/src/windows-emulator/syscalls.cpp
index 3551638d..01d3b070 100644
--- a/src/windows-emulator/syscalls.cpp
+++ b/src/windows-emulator/syscalls.cpp
@@ -3543,7 +3543,9 @@ namespace
         }
 
         c.proc.active_thread->save(c.emu);
-        const auto _ = utils::finally([&] { c.proc.active_thread->restore(c.emu); });
+        const auto _ = utils::finally([&] {
+            c.proc.active_thread->restore(c.emu); //
+        });
 
         thread->restore(c.emu);
 
@@ -3559,6 +3561,36 @@ namespace
         return STATUS_SUCCESS;
     }
 
+    NTSTATUS handle_NtSetContextThread(const syscall_context& c, const handle thread_handle,
+                                       const emulator_object<CONTEXT64> thread_context)
+    {
+        const auto* thread = thread_handle == CURRENT_THREAD ? c.proc.active_thread : c.proc.threads.get(thread_handle);
+
+        if (!thread)
+        {
+            return STATUS_INVALID_HANDLE;
+        }
+
+        const auto needs_swich = thread != c.proc.active_thread;
+
+        if (needs_swich)
+        {
+            c.proc.active_thread->save(c.emu);
+            thread->restore(c.emu);
+        }
+
+        const auto _ = utils::finally([&] {
+            if (needs_swich)
+            {
+                c.proc.active_thread->restore(c.emu); //
+            }
+        });
+
+        const auto context = thread_context.read();
+        context_frame::restore(c.emu, context);
+        return STATUS_SUCCESS;
+    }
+
     NTSTATUS handle_NtYieldExecution(const syscall_context& c)
     {
         c.win_emu.yield_thread();
@@ -3689,6 +3721,7 @@ void syscall_dispatcher::add_handlers(std::map<std::string, syscall_handler>& ha
     add_handler(NtUserGetCursorPos);
     add_handler(NtUserReleaseDC);
     add_handler(NtUserFindExistingCursorIcon);
+    add_handler(NtSetContextThread);
 
 #undef add_handler
 }