Dll errors and other issues on several pc's

Does anyone know if any of the programs out there for free or purchase will help in diagnosing some dll errors and trojans and such??? i have tried pc pit stop, it finds nothing to help me.

I have three pc's, all haveing problems. when surfing sometimes you see programs that say medical help for pc. or fix dll errors for free. does anyone know of some good trustworthy programs?????

below are just a few i can show you

1)Error C0000005 occurred in module mshtml.dll at address 7D4BB8B1
Stack Trace:
0 : mshtml.dll 0001:0001a8b1
1 : mshtml.dll 0001:00258fa8
2 : mshtml.dll 0001:002591a3
3 : mshtml.dll 0001:002592e1
4 : mshtml.dll 0001:000d55df
2)Product: Windows Operating System
ID: 1003
Source: System Error
Version: 5.2
Symbolic Name: ER_KRNLCRASH_LOG
Message: Error code %1, parameter1 %2, parameter2 %3, parameter3 %4, parameter4 %5.
3)Product: Windows Operating System
ID: 29
Source: w32time
Version: 5.2
Symbolic Name: MSG_NO_NTP_PEERS_BUT_PENDING
Message: The time provider NtpClient is configured to acquire time from one or more time sources, however none of the sources are currently accessible. No attempt to contact a source will be made for %1 minutes. NtpClient has no source of accurate time.

Explanation
The Windows Time Service cannot synchronize time with its time sources. Windows Time Service will attempt synchronization at a later time.

The W32time 29 message is usually caused by connectivity issues between a client and its source. In some cases, the source computer is unavailable; it may be restarting, disconnected from the network, or unreachable because of firewall or router configurations. If the W32time 29 condition persists, you should immediately troubleshoot the issue to ensure that successful synchronization can resume.
4) Product: Windows Operating System
ID: 57
Source: ftdisk
Version: 5.2
Symbolic Name: IO_WARNING_LOG_FLUSH_FAILED
Message: The system failed to flush data to the transaction log. Corruption may occur.
5)Product: Windows Operating System
ID: 51
Source: disk
Version: 5.2
Symbolic Name: IO_WARNING_PAGING_FAILURE
Message: An error was detected on device %1 during a paging operation.
6) trojan byte verify also on one of them
7)Your computer was not able to renew its address from the network (from the DHCP Server) for the Network
win xp home, 80+gbhdd,nvidia graphics,P 4,
Card with network address 000D3A210874. The following error occurred:
The semaphore timeout period has expired. . Your computer will continue to try and obtain an address on its own from the network address (DHCP) server.


I could go on with this but never the less, I do know how to research from google, microsoft.com etc... but half the time the stuff you read is WAY over my head.
the other half the time you get empty searches. So is there any help out there for this stuff in lay man's terms. I mean help for the pc newbie here!!!!
thanks for any advice.