PC won't sleep under windows XP, windows Vista, windows 7

In Run window type: cmd than press enter, than type "powercfg –devicequery wake_armed", press enter again.
Open run window again and type "devmgmt.msc".
Find any devices listed earlier, then double-click them and look for an Advanced or Power Management tab and see if the device is allowed to bring the computer to sleep. Click ok and close everything.

Missing taskbar icons in windows 7 or windows xp

Type on run box: regedit and go to:
 HKEY_CURRENT_USER\ Software\Classes\Local Settings\Software\Microsoft\Windows\ CurrentVersion\TrayNotify, and delete both IconStreams and PastIconsStream values.
Reboot!

Windows 7 taskbar problems

Click Toolbars > New Toolbar, type %userprofile%\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch in the folder box and click Select Folder. The Quick Launch toolbar should then reappear, and you can move and resize it to suit your needs.

iPhone don't sync in Windows 7

Disabling USB is the one solution. Click Start, type DEVMGMT.MSC and  to launch Device Manager, then click View > Devices By Type. Expand the Universal Serial Bus controllers section of the tree, right-click each USB Root Hub entry in turn, select Properties > Power Management, and clear "Allow the computer to turn off this device to save power".
Reboot your PC after this and try again.

Windows 7error: DVD drive not found

The standard solution here is to run REGEDIT, browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}, then delete both UpperFilters and LowerFilters in the right-hand pane (UpperFilters.bak and LowerFilters.bak entries can be ignored).

Windows Vista upgrade hangs at 62%

Reboot, and your PC should roll back to Windows Vista. You can then open the setup log file \$WINDOWS. BT\Sources\Panther\setupact.log to view what happened. Microsoft say this is usually caused because the Iphlpsvc service has stopped responding, and just adding an environment variable to ignore it will fix the problem. Point your browser at http://support.microsoft.com/default.aspx/kb/975253 for the fix.

How to fix ERROR_INVALID_BLOCK error?

9 (0x9)
The storage control block address is invalid.
Post a comment with your solutions for this error. Thank you.

How to fix ERROR_NOT_ENOUGH_MEMORY error?

8 (0x8)
Not enough storage is available to process this command.
Post a comment with your solutions for this error. Thank you.