I've been seeing the same bug on my HP dv5t laptop. Also Windows 7 RC 7100 build installed on it. Came looking here (and a few other places) to see if anybody else has seen it happen...
I reported the following "bug" on the Windows7 technet forums at Microsoft:
BUG: Explorer logon fails intermittently with partially loaded notification icons, non-functioning Start Menu.
This is an intermittent problem but happens consistently enough to be annoying (1 out of approx. 10 logon attempts). Every once in a while, when logging in to my account on Windows 7 RC, the explorer will fail to display all of the notification icons in the lower right corner. The icons which don't appear are: bluetooth, power, network, and sound. In other words, the "system" icons... In addition, when the system enters this state, the following additional symptoms are observed:
- The Start menu does not work completely. If you type in the search box, only the first character you type
is displayed, and no search is performed. Additional characters typed do not show in the search box.
- Hovering over pinned Taskbar icons do not show the normal highlight (the lines to the left and right of the icon).
- Running any program such as Task Manager results in strange display bugs. Menus left on the screen after being dismissed, client area of windows not drawing, etc.
Logging back out of the account, then logging back in will generally fix the problem, I think because the process causing the problem is killed/reset. In fact, I found that if I killed (it resarts itself) the DWM.EXE process (usually took a couple of trys) that the Start Menu functionality would come back. Thus, I think it may have something to do with DWM (Desktop Window Manager) during logon/explorer startup. You might be wondering how I killed DWM.EXE without being able to run anything from the start menu: Ctrl+Alt+Del to get to taskmgr.exe, then File.Run "procexp.exe" (Process Explorer from sysinternals.com) installed in root of C:, then (if running as standard user), File.Run As Administrator "procexp.exe" to get admin privs under Process Explorer, then use Process Explorer to kill DWM.exe.
I have observed this behavior only on one of my machines with Windows 7 installed (An HP dv5t). I have tried several different install scenarios, including upgrade over a Vista install approx 1 year old, upgrade over cleaned up (various crapware removed after running HP recovery to get to factory ship state) "HP Recovery" Vista install, clean install of Windows 7 RC x86, and clean install of Windows 7 RC x64. I have reproduced the problem both with all drivers applicable to the laptop and without (ie. just a clean install of Windows 7, standard VGA driver, stopping Windows Update from installing any drivers specific to the machine). I do not experience this problem on my desktop machine (A 6 year old Dell XPS Pentium 4 machine). Perhaps it is related to dual-core of the laptop (Intel P8600)?
HP dv5t, Intel P8600 @2.4Ghz, 3GB RAM, 250GB HDD.
NVidia GeForce 9600M, @1680x1050 (have tried running w/ Standard VGA driver, driver from Windows Update, driver from Nvidia 186.03, and driver from HP site)
IDT Sound (drivers from Windows Update)
Wired network RealTek RTL8168, drivers from Windows Update
Bluetooth (Microsoft Bluetooth Mouse 5000), default drivers
One other note: I do have multiple accounts enabled. One Administrator account: Admin, and two others that are standard users. I've seen this on all accounts.
Hopefully they took care of this one before the RTM build...