Downloads provided by Toshiba - Satellite P105-S9339
I see no reason that Win7 should not work satisfactorily on your laptop.
Test the hard drive (Hitachi HDP725050GLA360). Test the hard drive with the manufacturer's diagnostic utility.
*** EDIT: My mistake ... wrong HDD info .... SEE later post ***Download the Drive Fitness Test,
CD image from Hitachi's Downloads page.
http://www.hitachigst.com/support/downloads/#DFT
If you do not already have a suitable burning program for writing
.ISO images to disc ...
- Download and install ImgBurn.
Ensure that you UN-check the box agreeing to install the Ask toolbar during the installation. - Place a new (blank) CD disc in the drive tray.
- Choose Write image file to disc.
- Under Source, click on the Browse button: Navigate to and select the .ISO file that you wish to burn.
- Place a check-mark in the box beside Verify.
- Click

When the CD has been burned and verified as successful, it will be bootable.
Boot from the CD:
- Run the Quick/Short test and then the Extended/Long test.
Please post the results.
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Test the memory (RAM). I believe that you already have the bootable memtest86+ CD, but did not run the test properly (for at least 24 hours).
Memory needs to be tested outside of Windows, so
memtest86+ is run from a bootable CD.

To make a bootable CD with
memtest86+:
- Extract the downloaded zip file:
- Right-click on the zip file and choose Extract all. (Windows XP ... other Windows versions may have different wording.)
The contents of the zip file (the .ISO image file) will be extracted to a folder in the same location as your zip file.
- Burn the .ISO image to CD: If you do not already have a suitable burning program for writing .ISO images to disc ...
- Download and install ImgBurn.
- Ensure that you UN-check the box agreeing to install the Ask toolbar during the installation.
- Place a new (blank) CD disc in the drive tray.
- Choose Write image file to disc.
- Under Source, click on the Browse button: Navigate to and select the .ISO file that you wish to burn.
- Place a check-mark in the box beside Verify.
- Click

- When the CD has been burned and verified as successful, it will be bootable.

Boot from the newly created CD.
- You may need to configure BIOS or the Boot Menu to boot first from the CD.
- memtest86+ will begin running automatically: You need do nothing else at this time.
- Allow memtest86+ to run un-interrupted.
See the screenshots in this informative link:
Diagnose with Memtest86+There MUST be
NO errors what-so-ever:
- If you see an error, stop the test.
- Then proceed to test each stick of RAM separately to sort the good from the bad.
A
minimum test for some confidence in the result, should be
7 full passes (each "pass" is a series of different types of tests), with
NO errors.
- Allow memtest86+ to run for 24 hours for maximum confidence in the test result.
memtest86+ will continue running until you stop it:
- Press the <ESCAPE> key to re-boot the computer, removing the memtest86+ CD.
Reference: Overclockers forums Memtest86+ Guide/How To's
http://www.overclockers.com/forums/showthread.php?t=409152