Standby button grayed out/disabled

Since I installed Windows 7 Beta and even RC, I haven't been able put my computer into Standby. The button is grayed out and I have only been able to put it into hibernate
Any suggestions? Thx in advance

I personally think Microsoft could have done MUCH better here Sleep / Hibernate / Hybrid Sleep all very complicated .... I have tried for HOURS on all possible settings, including combinations with BIOS settings .... nothing!

In Vista, my home server used to 'wake up' my PC's (2 now with Win7), back them up, make them a cup of tea, tuck them back in, and made them go back to sleep again ... now NOTHING works, and I have been losing sleep trying to work this .... giving up on these settings until later. Mind you, to be fair, it is a VERY new O/S and very very pleased with it so far ...

Have you got the latest graphics card and chipset drivers? It could be that the default ones in use at the moment don't support standby mode.

Also, check in your BIOS to see if you have ACPI suspend mode enabled (should normally be Mode 3 STR).

I have seen BIOS updates for ACPI problems

What Ian has said. I have noticed that I cannot hibernate/sleep the system until I install current graphics drivers, and sometimes chipset drivers.

As said by Kougar and Ian, the graphics drivers, are almost always at fault to this problem, can you give us your specs, so we can find the graphics driver required

I have scanned for updated drivers using "DriverScanner" and all my drivers were up to date...
(I have an integrated graphics card with 64MB of VRAM. Apparently even most of the screensavers don't work due to it not being Direct X-compatible.)

Below are my computer specs:
CPU: Intel(R) Pentium(R) 4 CPU 3.00GHz
Manufacturer: Hewlett-Packard
Model: HP d530 SFF(DT903PA)
Total amount of system memory: 2.50 GB RAM
System type: 32-bit operating system
Number of processor cores: 1
64-bit capable: No
Storage Total size of hard disk(s) : 37 GB
Disk partition: (C: 19 GB Free (37 GB Total)
Media drive: (D: CD/DVD
Display adapter driver version: 6.1.7100.0
Primary monitor resolution: 1024x768
DirectX version: DirectX 8 or earlier

Do you know which graphics card you have? I'm sure we can get some better drivers for it. Could you go in to device manager and let us know (or run Belarc Advisor / Everest), as the HP website lists several graphics cards that could come with that PC.

Most look like they are nVidia graphics cards for that PC, but as it's an old one we'll need the exact model to get the right drivers.

thank you so much

to be honest with you the specs you have arnt magnificant foor the os, and surprised you can run it well, and as ian said please check the type of graphics as we will be able to give you the appropriate graphics drivers