I have had a HP 4500 four way wireless printer installed now for sveral months.  Occasionaly it gives my problems.   Lately it has refused print at all and I decided to un-install it and try to start over.   But I can't un-install it.  I get the error  message
      "THIS APPLICATION HAS REQUESTED THE RUNTIME TO TERMIMATE IN AN UNSUUAL WAY...  PLEASE CONTACT THE APPLICATION SUPPORT TEAM FOR MORE INFORMATION"
    Then I tried to un-install my HP 3970 scanner, which has never worked since I switched to Windows 7, with the same error message..   Needless to say I am unsucessful in contacting any "APPLICATION SUPPORT TEAM"  and I am getting frustrated.        
My system is as follows:
AMD  Athloon (tm)IIx4 640 processor,       4GB ram      Windows 7 64 bit OS     
Can anyone give me help on this.   Thank you in advance,   ...   JimWhen you say it is refusing to print is it being detected as available by the computer? Have you tried to connect via USB cable connection to see if it will work that way? Depending on your answers to these 2 questions it may assist in more clearly defining the area of the problem.truenorthTRUENORTH:   Yes, the printer acknowleges print commands from the computer (wirelss).   I have yet to try it via USB.  Will get back to you after I have done that.  Thanks,  JIMNot to be discouraging but just in case you should feel the urge to rush out and buy something have this in mind before you do. It appears that HP is offering this same unit for $59.95 with free shipping. http://www.shopping.hp.com/product/printer/office/1/storefronts/CB867A%2523B1H
In the interim while i am waiting for your reply re the USB i am doing some research on that unit. It seems like it was new in the XP era. Therefore i am concerned with it's compatibility with Win 7? Here is the link to driver/filmware/etc for that printer (but may not be applicable for win 7).
http://h20000.www2.hp.com/bizsupport/TechSupport/SoftwareIndex.jsp?lang=en&cc=us&prodNameId=1143084&prodTypeId=18972&prodSeriesId=1143083&swLang=8&swEnvOID=228
If it turns out to be an incompatibility with win 7 i would not recommend buying that model--no matter how cheap it is. However i get the impression that other than the scanner that before the ink cartridge issue it was working with win 7. Is that so? Also since you have had it operating with win 7 have you ever needed to replace a cartridge before?
truenorth TRUENORTH:   
    To answer your question, YES the printer/copier was working (wireless) before the cartridge issue.   
  Also YES when the original cartridge went dry, I refilled it but the printer would not print BLACK.   After inquiring around I was informed that HP often encodes their cartridges so that it knows when you are trying to use a re-filled one, and blocks it off.  So I bought a (supposedly) replacement cartridge on e-bay.  That cartridge worked very well until I had the problem with the "paper jam".  I had to remove the cartridge to clear the paper jam and when I put it back in, I got the message "CARTRIDGE INCOMPATIBILITY" and the printer/copier stopped printing at all.
             But since my last post, I tried the usb connection and was informed that I had to re-install the driver via CD.  Which I did...  Lo and behold, the printer/copier is now working just like it did (wireless) before my problems.  However, the scanner >computer link is still not working.  It never has worked.   Possibly because of the compatibility issue.   A friend of mine has this same printer, but he is using XP.  So what you are saying makes a lot of sense..
    Now that I know that the printer will work with this cartridge, maybe I will try to get it working again wireless.   (Or buy a loooong usb cable).   I wonder if I can use it with either usb or wireless.   Or usb with my desktop and wireless on the laptop.

In conclusion, either way,  I am good with my printing issues.  Thank you very much for your help.   I was beginning to pull my hair (what's left of it) out.

You guys have always been very good and helpful when I get in a jam.  You are deeply appreciated.  Sorry about the mixup with two strings,  I thot that I had two different problems.  Thanks again  JIM
jim.mar, A few comments. !st thank you for your kind words to me and to the CH forum members in general.
Now to address afew of your findings.
1.Because of the vintage of the printer and what it was designed to work with (XP) unless you can find drivers that are designed for Win 7 it may NOT be possible to ever get the scanner working on that O/S. But if a scanner is important to you then standalone versions are not expensive (plus another advantage to that will be forthcoming in a lower explanation on another part of this issue).
3. In the vast majority of todays modern all in one printers if for any reason one cartridge becomes unavailable (out of ink (actually usually a misnomer) etc) then ALL the functions of the device become unusable. I know this to be the case with many Canon models and while i don't know HP's handling of this on their machines i would not be surprised were it the same.
4.As i have so often pointed out on these forums with ink cartridges there are a variety of options available for the replacement/refilling of cartridges depending on your enthusiasm to save money and/or do things yourself. But often an after market (non manufacturer) replacement cartridge can be PROBLEMATIC.
5. Most printer manufacturers now emboss their cartridges with holograms that are specific to a printer and primarily designed to thwart the consumer to do anything but replace the cartridges at a specified  TIME interval with MANUFACTURER cartridges. Now this is where i deal with the relevance of my earlier comment re "out of ink" warnings that will usually bring about the loss of the machine until a cartridge is replaced. That is a misnomer because in fact it is not sensing a volume of ink level it is reacting to a frequency of utilization of the printer parameter (specific to a certain colour). Thus if your do a lot of document creation you will lose the black sooner than any of the other colours.
  As to whether you want to return to the wireless mode of course that is your choice, No guaranty as to the outcome though. My own tendency would be to STAY with the USB connected mode. I won't get into other issues with the wireless mode that probably aren't relevant to your case at the moment but suffice to say my wife has a Samsung wireless laser printer that she has decided to use only USB connected due to ongoing issues with the wireless mode.
truenorth
P.S. Re your 2 separate posts. In fact the subjects were different. But given that they pertained to the same printer and as you can now appreciate they were connected it would have not served you well to have some members contributing to one post and others to the other. It could have prolonged a possible solution and been confusing to all. But certainly no harm done.Yeah, I think that you are right obout thee 4500 being meant for XP.  My frieend has one also XP and it works quite well in all functions.
When the printer black cartridg ran out of ink it just started to fade away on black and finally quit altogether.  I tried refilling it and it did print one page ( which I believe was already in its memory) then refused to print blac at all.  It did not give any message, just wouldn't print.  Some one advised me to change the cartridge two or three times then repeat with the refill.   That didn't work either.  So I bought an after market cartridge on e-bay.  Put it in and it worked very well for a few weeks.   The  when I ha the paper jam and removd the cartridge to fix it, the printer put out the message,"CARTRIDGE INCOMPATIBILITY " when I tried to use it again.
It still did not wrok with the re-fill.   Now, after re-installing the driver and connecting the usb cable it is working the same as befor the paper jam with the newer cartridge...    I prefer refilling my old cartridges, been doing it for years, put I don't know how to get around HP's fix against that.  I also can't understand why teh printer went into the "CARTRIDGE INCOMPATIBILITY" mode until I had re-instlled the drivers.

COMMENT: The only two printers that I like are HPs and Canon, however, I live in Arizona and this hot dry climate is very hard on print cartridges.   Canon has (or had) their injectors in the carriage and was seprate from the ink cartridge and was much harder get them working again after re-filling, so I focused on using HP.

So, in conclusion, I will stay with the usb mode..  Thanks again for your help... JIM" I prefer refilling my old cartridges, been doing it for years, put I don't know how to get around HP's fix against that. "
Good on you. I have been doing that on a great number of printers for years with no downside to it.
Now about this part of the quote " put I don't know how to get around HP's fix against that." I have a commercial ink supplier in GA that i have used many times for things related to ink jet printers and can highly recommend. I have noted their contact on another post a long while back. Why i mention it again to you is that they also offer a variety of ways to overcome the manufacturers LIMITATIONS on their cartridges. It is not a one size fits all for each printer model has it's own specific option. I have no idea if they stock any or all of the options for your specific printer but if you are interested investigating that possibility just PM me and i'll give you the contact information and what to ask them.
 I have a possibility as to why the system works with the USB and not the wireless re the cartridge but it is just a guess.
truenorth