My PC is very slow and when I try to run check disk or defrag windows will not let me I also get a corrupt file C0000102, 75b6bf7c. Please advisesteve

In addition to the items below, I would start by testing the hard drive to make sure it isn't failing. Test the hard drive with a diagnostic utility downloaded from the drive mftr.'s website or use Seagate's SeaTools For DOS. You will create a bootable CD with the file you download. You will need third-party burning software to do this such as Roxio, Nero, or the free ImgBurn. Burn as an image, not as data. http://www.imgburn.com http://www.seagate.com/www/en-us/support/downloads/seatools/seatooldreg http://seagate.custkb.com/seagate/crm/selfservice/search.jsp?DocId=201271 (how-to) Boot with the CD you made and do a thorough test of the drive. If it fails any physical tests, replace it. Some other reasons for computer slowness: 1. Computer hasn't been maintained - http://www.elephantboycomputers.com/page2.html#Maintenance 2. Computer is infected with malware - http://www.elephantboycomputers.com/page2.html#Removing_Malware 3. Hard drive is too full. Remove unnecessary stuff, uninstall unused programs. Don't forget to back up! http://www.elephantboycomputers.com/page2.html#Backing_Up 4. Flaky third-party software. Toolbars and add-ons are particular culprits in this area. Uninstall toolbars (Google, Yahoo, ISP-branded, etc.) and look carefully at what add-ons are in use in your browser(s). 5. Computer has too many unnecessary programs/processes running in the background. Manage your Startup: For XP - How to Troubleshoot By Using the Msconfig Utility in Windows XP - http://support.microsoft.com/?id=310560 The free Autoruns program is very useful for managing your Startup - http://www.microsoft.com/technet/sysinternals/default.mspx For Vista/Windows7 - Start Orb>Search box>type: msconfig and when it appears in the Results box above, right-click and choose "Run as Administrator". Autoruns is also very useful. 6. User is running a bloated/invasive antivirus program such as ones from Norton and McAfee. Replace with a better program. I recommend either NOD32 (commercial) or Avast (free). Avira is also good but the free version has an unpleasant nag screen (Google for instructions as to how to disable this). User may also be running more than one real-time antivirus/firewall/security program. 7. User has installed new programs that are processor and/or memory-intensive (Photoshop, AutoCAD, Mathmatica or the like) and doesn't have the necessary hardware power. 8. Hard drive is failing and is in PIO Mode. This is very dramatically slow (like being back in 1985). See Hans-Georg Michna's information here - http://winhlp.com/?q=node/10 In addition to the above, also see http://miekiemoes.blogspot.com/2008/02/help-my-computer-is-slow.html MS-MVP - Elephant Boy Computers - Don't Panic!