Windows 7 - 4gb of RAM installed, but w7 says 256 usable

Earlier tonight I rebooted and noticed that it took an extremely long time to boot. Almost 10 minutes to get the desktop completely loaded. So I checked task manager > performance tab and it says I have only 256mb of RAM. So then I checked My Computer > Properties and noticed it said "Installed Memory (RAM): 4.00 GB (256 MB Usable)" I've had Windows 7 installed for a good 2 weeks now and never had a problem, until I rebooted tonight. I checked my BIOS and all my sticks show up. I DO NOT have a shared memory video card. Memory test checked out fine. I haven't installed any new hardware, nor touched the sticks at all. Any idea as to why Windows 7 started doing this?

Have you fiddled with the boot settings at all? And welcome to the forums.

Nope not at all. Everything was running perfectly fine until I rebooted. Now this things running like winME on 64mb.

installed any new programs? something may needs drivers?

Nope. I managed to find and fix the problem tho. Somehow the MAX ram settings in the advanced tab of boot config got set to 256mb. I unchecked the box, rebooted and everything is fine now.

Anything installed/updated/messed with sence the last reboot?...I dont believe that can accidently be check, unless a program has altered the setting in some way

Nothing was installed, messed with etc..