diff --git a/os/part3/os.bin b/os/part3/os.bin
index 4753e09..b588bbb 100644
Binary files a/os/part3/os.bin and b/os/part3/os.bin differ
diff --git a/os/part4/kernel/isr.asm b/os/part4/kernel/isr.asm
index fa69fb2..123f2be 100644
--- a/os/part4/kernel/isr.asm
+++ b/os/part4/kernel/isr.asm
@@ -176,7 +176,7 @@ ISR_systimer:
     inc qword [abs tasktimer_ticks]
     cmp qword [abs tasktimer_ticks], 1 ; Every how many ticks we want to switch tasks.
     jle .no_switch
-    cmp [abs num_tasks], 0             ; No tasks to switch
+    cmp qword [abs num_tasks], 0       ; No tasks to switch
     je .no_switch
    
     ; set tasktimer_ticks to 0
diff --git a/os/part4/os.bin b/os/part4/os.bin
index d940bb4..3c53b30 100644
Binary files a/os/part4/os.bin and b/os/part4/os.bin differ
diff --git a/os/part5/kernel/isr.asm b/os/part5/kernel/isr.asm
index 9c37970..13e44ad 100644
--- a/os/part5/kernel/isr.asm
+++ b/os/part5/kernel/isr.asm
@@ -171,7 +171,7 @@ ISR_systimer:
     inc qword [abs tasktimer_ticks]
     cmp qword [abs tasktimer_ticks], 1 ; Every how many ticks we want to switch tasks.
     jle .no_switch
-    cmp [abs num_tasks], 0             ; No tasks to switch
+    cmp qword [abs num_tasks], 0       ; No tasks to switch
     je .no_switch
    
     ; set tasktimer_ticks to 0
diff --git a/os/part5/os.bin b/os/part5/os.bin
deleted file mode 100644
index 391178f..0000000
Binary files a/os/part5/os.bin and /dev/null differ