I have upgraded Windows XP Home to Windows XP Pro and suddenly there were only two options on the Start-Shut Down button, namely Shut Down and Restart. Stand By was greyed out and there was no Hibernate option. I looked and looked and Googled and read through various posts on the internet but there were only puzzles to be put together. However, after two hours I managed to find the solution. A lot of people claim that you've got to go to Power Options in the Control Panel and enable Hibernation there but my problem was that option was unavailable. There was nothing anywhere on Hibernation or Stand By. Should you have a problem like that then please take the following steps:
1. If you have Windows XP Pro SP2 then either upgrade to SP3 or download the KB893056 hotfix from Microsoft Support and follow instructions provided within to update Registry (be careful and do exactly as they suggest!!!). Please bear in mind that Microsoft will require your e-mail address as they will send you a download link separately but it is a straightforward process once you receive the link. Just download and extract it to your desktop and double-click the extracted files.
2. After you complete the above press Start button and then Turn Off your computer. You should see 4 options In the "Turn Off Your Computer" dialog box (Hibernate, Stand By, Shut Down and Restart).
3. If Hibernate and Stand By options are still greyed out open Control Panel -> System -> Hardware (tab) -> Device Manager and check if any of the listed devices are highlighted with a yellow questionmark. The greyed out problem is a result of a missing/inappropriate video driver so check Display Adapters and it should be highlighted (i.e. it will probably be Other Adapters at this stage). Leave Device Manager open once you identified highlighted Other Adapters as you will use this window for updating (step 5).
4. Check the support sites of the computer manufacturer and search for a video driver for your model. In my case the problem happened with Sony VAIO and I simply downloaded and extracted the 16MB ZIPPED video driver on the Desktop. Remember the location of extracted files as you will need this later in the Hardware update Wizard to locate your drivers (step 6).
5. Go back to device manager (the last sentence in step 3) right click on the "problematic" questionmark-highlighted Display Adapters (i.e. Other Adapters), use your mouse to right-click on one of them and select Update Driver.
6. This will open the Hardware Update Wizard where you first select "Yes, this time only" and click Next. Click "Install the Software Automatically" and select "Browse to locate the drivers". Select one of the sub-folders in the extracted folder from step 4 and the Wizard will do all the rest. When finished you should not have any highlighted problems in your Device Manager and Other Adapters should now say Display Adapters.
7. Exit all applications and restart the machine. After restarting you will have all four options available but Hibernate will most probably still be greyed out.
8. If Hibernate is still greyed out but you wish to have it activated go to Power Options in the Control Panel (Start -> Settings -> Control Panel -> Power Options). You will suddenly see Hibernate tab where you can enable it but make sure that your "Free disk space" is much greater than "Disk space required to hibernate". You can then also set your laptop to Hibernate if you close the lid. This will allow you to go away but leave your files open and applications running. I like this option as it means I can safely leave my laptop without completely switching it off - prevents overheating and enables quickly starting where I finished earlier! To do this click on the Advanced tab and under "Power buttons" select Hibernate for "When I close the lid of my portable computer".
Voila, you're done. I know it appears as a lot of steps but in essence it took me less than 20 minutes to do all of the above once I knew what needs to be done.
