No boot option for Win7 after installing Lubuntu

[mahesh]

I had a working win7 installation on a thinkpad 0328a11 (celeron, bit of an older laptop) & wanted to try out Lubuntu. Installed Lubuntu 22.04 and resized the 160Gb hdd into 2 80Gb partitions in the install program from the Lubuntu live desktop. Lubuntu works GREAT but I don't have any boot options for going into Win7. I don't have any important win7 programs that I need to run off this laptop, I was using this laptop as a testbed for Lubuntu installs on other pcs. I can easily find and mount the win7 partition & all the data seems to be there. I gather that grub/lilo or something has overwritten the mbr but I am very new to linux/Lubuntu so not sure as to exactly what has happened or how to fix this. I am pc literate for 40 years (win/dos/osx environments) & have no problem with losing the win7 partition or rewriting or re-installing the whole lot if needed, but what I really want is either to know where I went wrong or how to fix this so that when/if I install Lubuntu on my other pcs that I know what I'm doing.
thanks to all for any help provided