Even if you aren’t getting blue screens, but still having problems with your computer getting stuck coming out of sleep mode, there are several things you can do to help remedy the problem. First, you should defrag your hard drive. This will make it easier for Windows to save and load all the data required to take the computer in and out of sleep mode, plus it’s generally helpful to everything on your computer because it makes the files quicker to access.
Another thing to look at is all the peripherals connected to your machine. I have an iPod Touch and sometimes my PC does weird things when booting up or coming out of sleep mode while the Touch is plugged in via USB. I suspect it has something to do with it wanting to recharge the battery while simultaneously loading and syncing iTunes. Unplug anything you don’t normally use and see if your PC works better after that.
If your problem is related to hardware that is wearing out, then you may have to consider replacing them at some point. Running Windows Update to get all the current software and driver updates always helps to keep the PC running more smoothly. If you can’t find any other problems with your computer besides sleep mode not working, then the easiest solution is to disable sleep mode.