Win7 "Task Manager" has lost its header tabs

Question

Somehow the task manager has lost the header tabs to move from applications to processes to network. It was there originally.
I also lose from time to time my volume control icon, and it doesn't become hidden, it just disappears completey. To change the volume I have to either go into the control panel/sound and then adjust the volume and leave that open if I need to turn it down. OR reboot and it sometimes comes back.
When I go to 'notification Icons" in control panel the icon and lettering for sound icon is not bold or high lighted but instead it is diminished. I have also seen a popup stating that modification will take affect when it (the sound) is activated as a pop up, but can't remember where I saw that happen. 
Another question I have is...
Ihave only one machine, my C:drive has Vista ultimate, all important files are on E,F HD's, removable, or external drives. I downloaded Win7 and burned a disk.
I removed the 40Gig C: with Vista  put a 250Gig drive in that location and installed Win7. So far so good and am very pleased with everything even with a few bugs.
Now I needed to go back to the Vista drive, so I removed the Win7 drive, reinstalled the 40Gig as C and received a prompt stating that ? win logon was not found. So I got the Vista DVD and did a repair which worked. If Win7 doesn't get an update to operate past August 1st and I go back to the 40Gig Vista drive will that happen again? AND where does that file get stored when you originally install? Does it go into the bios chip? Only becasue when I went back to the Win7 HD I got virtually the same prompt for that other drive.
I am in the process of building another machine, but because the computer I'm currently using is antiquated in comparrison and all new parts are required except for the chasis the cost is setting me back a bit. Maybe when I do get everything I'll be able to do a dual OS, but for now I have what I have. Computer is an old dual xeon with ata drives going on 7yrs old, but has been a work horse and needs to go to pasture.   

Answer 1

In addition to what Techoutsider said, you can open the Notification Area Icons control panel item and you can try clicking the "Restore default icon behavior" link near the bottom of the window and see if that fixes the MIA volume control.
Your issue with swapping the hard drives may have something to do with the BIOS. Namely, it may not have correctly registered the replaced drive the first time you rebooted. You may want to try going in and making sure that it's where it should be in the pecking order. If it's expecting the 40 GB HDD, and it suddenly finds a 250 GB HDD, that could be the reason why you're having difficulty booting. Simply removing the drive and swapping it out should not cause it to become unbootable unless something changed within the BIOS settings. Given the drives you've got there aren't identical, there may be an issue with the BIOS not finding the correct drive. Make sure you update the BIOS settings by going in and then saving while exiting.
For the record, NO OS writes ANYTHING directly to the BIOS. The exceptions to this would be the utilities you get with your motherboard that allow you to tweak settings (overclock) your components - such as Nvidia's NTune applet. All Windows files get written to the hard drive. As long as you didn't change anything, it should be able to find everything as it was the last time the hard drive was plugged in.
According to rumors and such, there should be an RC build available almost any time now. There have been rumors to April 10th - or 1 week from this writing - and there have been rumors to some time in May.