Hi.
I reviewed the OTS log.
Shows no traces of active infection than possible infections that came via USB portable devices. We will check this later…
MBRCheck shows some irregularities. (read this as “possible rootkit” ) 
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[*]Download TDSSKiller and save it to your Desktop.
[*]Unxip the folder (Right Click > Extract to your Desktop).
[*]Once extracted, open the TDSSKiller folder and doubleclick on TDSSKiller.exe to run the application, then on Start Scan.
[*]If an infected file is detected, the default action will be Cure, click on
[*]If a suspicious file is detected, the default action will be Skip, click on Continue.
[*]It may ask you to reboot the computer to complete the process. Click on Reboot Now.
[*]Click the Report button and copy/paste the contents of it into your next reply
Note:It will also create a log in the [b]C:[/b] directory.
Then download aswMBR to your desktop.
[*] Double click the aswMBR icon to run it.
[*] Vista and Windows 7 users right click the icon and choose “Run as administrator”.
[*] Click the Scan button to start scan.
[*] When it finishes, press the Save log button, save the logfile to your desktop and post its contents in your next reply.
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Olso you may try to repare your system with SFC command:
- Locate your Windows XP installation CD
- Go to Start, then to Run, and type in “SFC.EXE /SCANNOW” (without the quotes - and with a space between the SFC.EXE and the /SCANNOW).
- Press Enter.
- The program may (or it may not) ask you for your Windows XP installation CD - please insert it at the prompt. If it doesn’t ask you for the CD this means that it wasn’t necessary to replace any files.
- In the event the the system asks you for the CD, you must visit Windows Update immediately after the scan is completed (Please note that there won’t be any confirmation dialog - the program will just exit without telling you anything).
Info:
http://www.updatexp.com/scannow-sfc.html
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Paste here TDSSKiller & aswMBR logs.