If you press Esc key while Resuming Windows then the process will pause and to resume it you have to press Esc key. If you didn't press the key then there can be a RAM or Virus problem. First downld a good antivirus like QuickHeal from
www.quickheal.co.in then update it's definition and scan your computer. Try reinstalling your Windows. If this also didn't work then downld Windiag. Burn it's iso image to CD and boot from it then if it find any error then open your cabinet and install the RAM in other slot if you get an error then it will a RAM problem. (Note: Open the cabinet after shuttng down your computer.)