Sleep grayed out - cannot restore

I disabled sleep on my computer when the monitor would not wake after being in sleep mode. A new video card was added and now that problem is solved. However, I no longer have "sleep" as an option on the start menu or after the user's log out. The options left on the start menu are (a) Switch User; (b) Log off; (c) Lock; (d) Restart; (d) "grayed out" sleep; (e) Shut Down.

After a log off, the only options available are (a) Restart; and (b) Shut Down; Sleep has disappeared.

Under Control Panel, Power Options, I made changes to allow the computer to sleep (on all of the power plans including the 'show additional plans')--- but sleep is still dimmed on the start button and after logging off.... also tried tochange the "when I press the sleep button" which is located under'choose what the power buttons do' which is to the left of the select a power plan.... restarted numerous times; shut down & left overnight and then tried again, but still a dimmed sleep. Can anyone help?

Welcome
If you would settle for hibernate, this may help
http://www.vistax64.com/tutorials/74022-hibernate-shortcut.html

I really do not want to hybernate....do want to restore the sleep function that was on the start menu and also after logging off. At night, I want to put my computer to sleep so that the fans are not running and the computer will come back to life with the swish of the mouse. I was able to do a cmd (powercfg -h on") and now I do have hybernate. But both my husband and I use this computer and we always log off after finished. I also did a cmd (powercfg -h off) which I was told would then put sleep mode back in, but sleep is still grayed out! This is so frustrating and certainly not an easy fix....:sa:

OK
Several things to try
Go to search by the start button
type device manger
In device manger look for any small yellow pointers indicating that there is a problem.
Update your graphics driver
and
display adapter driver

Run an SFC check
http://www.vistax64.com/tutorials/66978-system-files-sfc-command.html