Here is a util that might be useful to someone (Its just a checker) but it will at least hopefully tell you where a fault lies (its 2.4mb download)
We give you the diagnostic tool FREE & you only pay to lease a security key to unlock "PcDocRx OnCall" which fixes the problem - if no problems are found you pay nothing!
FREE diagnostic tool "PcDocRx OnCall" has been designed to seek out potential Windows problems on your PC, with simplicity of use in mind.
"PcDocRx OnCall" performs a series of diagnostic checks to locate file errors & problems, including all types of software errors, registry problems, leftovers from incomplete uninstalls (Norton Antivirus/works, Zone Alarm Pro etc), invalid registry entries created by viruses & much more.
An entirely new strategy called "LEASEWARE".
Here is the URL if anyone's interested...
PcDocRx OnCall