I've gone through almost all previously posted threads on this topic but none of them really helped me fix the problem. Hence i chose to post it again.
Laptop: Dell Studio 1558 (core i5)
OS: Win 7 Home Premium (pre-installed) 64-bit
Free space on C: = 12GB
No Virus and malware exists
1. "Windows Update" recommended to install SP1 and i chose to go ahead but it failed with error 0x80004005.
2. Then i downloaded windows6.1-KB976932-X64.exe (~920MB) and tried to install but failed at 99% (configuring service pack) with same error 0x80004005
3. Then i followed Windows 7 SP1 installation failed with error 0x80004005 E-FAIL - Microsoft Reduce Customer Effort Center - Site Home - TechNet Blogs
and did the below
a. Installed "System Update Readiness Tool" (Windows6.1-KB947821-v12-x64.msu - ~ 320MB)
b. ran "sfc/scannow" - it found few errors and fixed automatically.
c. Verified if "0x8004a029" found in cbs.log but it does NOT have any
d. Disabled Symantec AV completely
e. Tried again applying SP1 but again failed at 99% with same error 0x80004005.
Wonder if anyone had success with SP1 inst and I don't want to do fresh reinstallation of OS as I have lot of applications.