Nothing Malicious in the log. I'm guessing the laggyness is just from too many process running at once or too much space is taking up by uneeded programs.
Heres a couple things you can do to help with that.
Go to the start menu and then run. Type "msconfig"(without the quotes) into the box. Now go to the startup tab. Uncheck any boxes that have programs next to them that dont need to load when you first turn the computer on, such as QuickTime Task, or microsoft office. This will make the computer turn on faster.
Now i would like you to download and install the following program to delete temp files and folder you don't need.
Begin by downloading CCleaner , and specifically choosing the most recent version.
Then, follow these steps:
1. Close all programs so that you are at your desktop.
2. Double-click on the "My Computer" icon.
3. Select the "Tools" menu and click "Folder Options".
4. After the new window appears select the "View" tab.
5. Place a checkmark in the checkbox labeled "Display the contents of system folders".
6. Under the "Hidden files and folders" section select the radio button labeled "Show hidden files and folders".
7. Remove the checkmark from the checkbox labeled "Hide file extensions for known file types".
8. Remove the checkmark from the checkbox labeled "Hide protected operating system files". 9. Press the "Apply" button and then the "OK" button and shutdown My Computer.
10. Now your computer is configured to show all hidden files.
Now, install the program. Open it, and choose the 'Options' tab. Inside, hit the 'Custom' tab, and add the following folders (Note: Not all of these files are on every computer. If one of these isn't present, skip it):
C:\Windows\Temp
C:\Temp
C:\Documents and Settings\\Local Settings\Temp
C:\Documents and Settings\\Local Settings\Temporary Internet Files\Content.IE5
C:\Documents and Settings\\Local Settings\History
C:\Documents and Settings\\Cookies
C:\Windows\Prefetch
After doing this, move back to the 'Cleaner' tab, and inside this, be sure your open to the 'Windows' tab. Inside, check the box labeled 'Custom Files and Folders'.
Next, after following all of these steps, you're ready to scan. Run scans in both the 'Cleaner' and 'Issues'. Note: It might take several scans in each to remove all of the junk.
I would also advise that you and your sister go through C:/Programfiles/ and My documents and delete anything that isn't needed anymore. Also run CCleaner after you do this. Hope this helps speed up the comp a little.