Hello,
As well as some of the steps already mentioned, also do the following:
1. Check the disk for any errors. Run command prompt and type
CHKDSK x: /R where
x: is your operating system partition.
You'll be asked whether you'd like to scan upon next boot...make sure you answer yes to this. Reboot the machine to start checking the disk.
2. Secondly I'd check to see how heavily fragmented the drive is. Go to
Control Panel >
Administrative Tools >
Computer Management >
Disk Defragmenter click to analyze all your partitions, and defrag them if needed - one at a time.
3. Next try running Microsoft Bootvis, downloadable here:
http://www.majorgeeks.com/download.php?det=664
Use it to optimize the boot process.
4. If you've installed CCleaner, open it and on the left, click
Issues. Scan for issues, and then fix any issues found.
5. Download
Sysnternals PageDefrag, extract it to a folder and run the program. Select to
Defrag at next boot and click ok. Reboot the machine.
6. You might also want to perform a thorough system scan using Avast! Antivirus if you haven't done so already.