--- a/toolkit/components/aboutprocesses/tests/browser/browser_aboutprocesses.js
+++ b/toolkit/components/aboutprocesses/tests/browser/browser_aboutprocesses.js
@@ -361,17 +361,17 @@ add_task(async function testAboutProcess
     let children = threadRow.children;
     let tidContent = children[0].textContent;
     let cpuUserContent = children[3].textContent;
     let cpuKernelContent = children[4].textContent;
     ++numberOfThreadsFound;
 
     info("Sanity checks: tid");
     let tid = Number.parseInt(tidContent);
-    Assert.ok(tid > 0);
+    Assert.notEqual(tid, 0, "The tid should be set");
     Assert.equal(tid, threadRow.thread.tid);
 
     info("Sanity checks: CPU (user)");
     testCpu(
       cpuUserContent,
       threadRow.thread.totalCpuUser,
       threadRow.thread.slopeCpuUser,
       HARDCODED_ASSUMPTIONS_THREAD

--- a/widget/windows/ProcInfo.cpp
+++ b/widget/windows/ProcInfo.cpp
@@ -131,40 +131,45 @@ RefPtr<ProcInfoPromise> GetProcInfo(nsTA
             return;
           }
 
           nsAutoHandle hThread(
               OpenThread(/* dwDesiredAccess = */ THREAD_QUERY_INFORMATION,
                          /* bInheritHandle = */ FALSE,
                          /* dwThreadId = */ te32.th32ThreadID));
           if (!hThread) {
-            // Cannot open thread. Not sure why, but let's attempt to find data
-            // on other threads.
+            // Cannot open thread. Not sure why, but let's erase this thread
+            // and attempt to find data on other threads.
+            processLookup->value().threads.RemoveLastElement();
             continue;
           }
 
+          threadInfo->tid = te32.th32ThreadID;
+
+          // Attempt to get thread times.
+          // If we fail, continue without this piece of information.
           FILETIME createTime, exitTime, kernelTime, userTime;
-          if (!GetThreadTimes(hThread.get(), &createTime, &exitTime,
-                              &kernelTime, &userTime)) {
-            continue;
+          if (GetThreadTimes(hThread.get(), &createTime, &exitTime, &kernelTime,
+                             &userTime)) {
+            threadInfo->cpuKernel = ToNanoSeconds(kernelTime);
+            threadInfo->cpuUser = ToNanoSeconds(userTime);
           }
 
+          // Attempt to get thread name.
+          // If we fail, continue without this piece of information.
           if (getThreadDescription) {
             PWSTR threadName = nullptr;
             if (getThreadDescription(hThread.get(), &threadName) &&
                 threadName) {
               threadInfo->name = threadName;
             }
             if (threadName) {
               LocalFree(threadName);
             }
           }
-          threadInfo->tid = te32.th32ThreadID;
-          threadInfo->cpuKernel = ToNanoSeconds(kernelTime);
-          threadInfo->cpuUser = ToNanoSeconds(userTime);
         }
 
         // ----- We're ready to return.
         holder->Resolve(std::move(gathered), __func__);
       });
 
   rv = target->Dispatch(r.forget(), NS_DISPATCH_NORMAL);
   if (NS_FAILED(rv)) {