You've just run G-Spot, Sherlock the CODEC Detective, or another CODEC utility, and get all sorts of pink or red notations on your Adobe/MainConcept CODEC's, reporting that they are broken, or corrupted. Scary, huh?
What you see in those pink or red highlighted entries are "false positives". Adobe uses a slightly different naming convention for its CODEC's (all MainConcept here), to protect them from being replaced, or corrupted by other programs. Many other programs, like CODEC "packs" will go into one's computer and replace good, commercial CODEC's with hacked, free versions. Sometimes this works OK, but often things just do not work as well after the CODEC pack. By hiding them, there is far less a chance that they will be messed up by another program. Unfortunately, this naming convention is not understood by most CODEC utilities, like G-Spot, or Sherlock the CODEC Detective. They see the correct link to the CODEC in Registry, but cannot find it in the system folders. Hence, they report that there is a problem. This has been heavily documented in the fora, but usually within thread on another problem. This means that the casual user, even with a Search, might not turn up the info. It's too bad that those utilities have not been rewritten to find the Adobe/MainConcept CODEC's, or that they do not have an info message, telling their users that all is really OK.
Hope that this lets you sleep better, and saves your trying to reinstall your Adobe video editing program. That is not necessary.
One thing that CAN happen, even with the naming convention to hide the CODEC's is that other programs, or CODEC "packs" can alter the OS's priority of the CODEC's, effectively telling the system to use another CODEC, other than the Adobe/MainConcept ones, for certain AV files. This can mean that your fully functional Adobe MainConcept CODEC's are down the list, and you're dealing with some hacked, or reverse-engineered version, rather than the commercial version, that was included in your Adobe program. This often goes totally unnoticed, but can also cause issues. The cure for this is to edit the Registry, but this is not for people, who do not know exactly what they are doing. I will not go into the process of this, as anybody, who does know how to safely hack their Registry will know how to do this, but anyone, who does not know what to do, should not attempt to do it - things can go very wrong and in a hurry. Those people would be better off just doing a Repair Installation of the Adobe program, and let that rewrite the entries in the Registry.