This is a Dell Inspiron 1525 laptop running an OEM Vista 32 bit x86 OS and wouldn't boot to desktop half the time. The system was inundated with adware, spyware and some malware and was quite unstable [each restart presented differing errors and problems].
The first actions taken were to run SFC and CHKDSK. SFC found files that it couldn't repair and are recorded in the CBS logs. CHKDSK found several missing files and corrupted sectors which were corrected.
Then, loaded and ran Malwarebytes AV [MBAM] which identified some innocuous adware etc. plus Trojan.zekos.patchedwv0 - these were supposedly cleared! On restart, various hangs were encountered - no two alike! A 2nd pass at CHKDSK identified literally 1,000's of files that had invalid security IDs which were replaced by default IDs. At this point, I "gave in" and ran a rebuild of the OS using the Dell Reinstallation disk which, of course, required downloading all of the Updates [over 180 total]. I'm not sure if the Dell drivers are the most current.
Now I'm practically back to square one! So, re-ran MBAM - no errors; Downloaded and ran Malwarebytes Anti Rootkit [MBAR] which found the and removed the same Trojan. A 3rd pass of both MBAM and MBAR were non-eventful!
Now I hoped to complete the upgrades by installing SP1 then SP2 to bring the system up-to-date.
SP1 will not install so I'm turning to your forum for some comfort and advice!
Thank you, WJG641