try disabling fast shutdown, if it isn't already:
Click Start, point to Programs, point to Accessories, point to System Tools, and then click System Information.
On the Tools menu, click System Configuration Utility.
On the General tab, click Advanced.
Click to select the Disable Fast Shutdown check box, click OK, and then click OK.
Click Yes when you are prompted to restart your computer.
Click Start, point to Programs, point to Accessories, point to System Tools, and then click System Information.
On the Tools menu, click System Configuration Utility.
On the General tab, click Advanced.
Click to select the Disable Fast Shutdown check box, click OK, and then click OK.
Click Yes when you are prompted to restart your computer.