JudasIscariot:

UK_John: I finally gave up on Oblivion last week. I had put 200 hours into it, but about a month ago noticed there were some good quest mods, like Thieves Arsenal and the Lost Spires mods. I was merrily playing the game not having added any mods in 5 weeks and not have tweaked the ini or anything in months, and not having changed any drivers or anything in my PC in at least a month, out of the blue, I cannot talk to any live NPC! Hit 'E' to talk to them and the game crashed. Checked their inventory when they were dead wasn't a problem, but if they were alive game crash every time!I tried reinstalling (which meant reinstalling some mods too!) but the problem was still there! At that point I just gave up as Fallout 3 was on the horizon!
Of course, Fallout 3 uses the same Oblivion engine, so when I decided to install a better skin mod I checked to see what folders/files it installed to and then backed those folders/files up first! I then installed the mod and checked the game - sure enough, purple hands and face (yes, I did update the archiveinvalidation.txt!) I wen back into the install folder changed the archiveinvalidation and removed the folders/files. I then copied back the original files and I still had the purple face and hands! Only the Oblivion engine can defy logic like this!
Needless to say, I had to reinstall Fallout 3 having first deleted those files and folders to make sure Fallout installed the working files!
Having said all the above Fallout 3 is seen as a lot more stable, but that's because no one has installed any major mods yet as there is no CS!
I would also say that when people talk about how great a game Oblivion is on PC, they are not talking about vanilla Oblivion, they are talking about an Oblivion improved by 50+ mods! :)

UK_John: JudasIscariot - yes I did.You have to remember I had been playing for a long long time with no problems, And it had been 5 weeks since installing any mods and during those 5 weeks no problems. I went back to previous saves, I reinstalled, I backed up my Oblivion.ini and let Oblivion create a new one, and I could not get the problem fixed. More annoying was the fact there was no logic to the problem occurring! I had not just installed a mod, I had not just changed my load order, I had not just changed graphic drivers or anything - nothing was different! It was just like Oblivion decided to go wrong or some program code corrupted. I am sure if I uninstalled everything, including all mods, etc. Reinstalled and started a new game I could probably get the game to work (although could also get another set of problems!), but I don't want to start the game again. So in effect, this problem was the final straw. So I uninstalled, deleted the Oblivion folder, cleared out the registry and now have nothing on my drive at all.

JudasIscariot: Yeah it's weird how today's games just decide to go a bit wonky isn't it?? I hope it doesn't happen to mine...although it has been crashing to desktop more often now. Maybe it's a very virulent case of bitrot???

UK_John: Yes - that's it! bitrot! Or in my case byterot! Crashing to desktop is a pain,but it doesn't stop you playing - have you tried playing the game without speaking to anyone?! No quests, no joining any guilds, no getting Martin to follow you..... It's the one problem that absolutely kills the game! :(

UK_John: Regardless to how many or how few mods you had - if you had been playing the game with no problems for over a month wouldn't you say quite bluntly that there cannot be anything wrong with any mod installation or mod order?! Because it had been 5 weeks since I had done anything like that I was confident all was well on the mod side. So as said above, I believe this was an Oblivion engine thing.
Just like my example with FO3. How the hell can you put the original files back in their relevant folders and still have the problem that the mod you install caused? I mean by removing the mod files and replacing them with the original files surely surely puts the game back to where it was - but oh no - not the Oblivion/FO3 engine. That has a mind of it's own and logic goes out the window - as with my Oblivion problem. So two games, both using the same engine, both doing something that is technically illogical.

Fluofish: There is also the possibility that you installed something completely different that conflicts with the general handling of the game.
I'm talking about cases where like a virus scanner that is conflicting with an online game etc. Issues with a program are not necessarily because direct changes to the same program, they could also be caused by something completely different

Fluofish: Pffft
I'll make sure that it remember "that" next time you come to me for help :p
I hope you two will be very happy with each other